Essential Terms Organic Chem Ch 1-11

Helpfulness: +1
Set Details Share
created 5 years ago by OceansVoice
445 views
book cover
Organic Chemistry
Chapters 1-11
Essential terms at the end of each chapter
updated 5 years ago by OceansVoice
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:
1

Acid

dissociates in water to give H3O+

proton donor

electron pair acceptor (electrophile)

2

Base

dissociates in water to give -OH

proton acceptor

electron pair donor (neutrophile)

3

isotopes

atoms with the same number of protons but different numbers of neutrons; atoms of the same element but with different atomic masses.

4

electrophile

an electron pair acceptor

5

neutrophile

an electron pair donor

6

line-angle formula

A shorthand structural formula with bonds represented by lines. Carbon atoms are implied wherever two lines meet or a line begins or bends. Atoms other than C and H are drawn in, but hydrogen atoms are not shown unless they are on an atom that is drawn. Each carbon atom is assumed to have enough hydrogens to give it four bonds.

7

organic chemistry

The chemistry of carbon compounds.

The study of compounds derived from living organisms and their natural products.

8

acid chloride

an acid derivative with a chlorine atom in place of the hydroxyl group

9

alcohol

a compound that contains a hydroxyl group bonded to a carbon atom;

R-OH

10

aldehyde

a carbonyl group with one alkyl group and one hydrogen

11

alkanes

hydrocarbons containing only single bonds

12

alkenes

hydrocarbons containing one of more C=C double bonds

13

alkyl group

a hydrocarbon group with only single bonds; an alkane with one hydrogen removed, to allow bonding to another group; symbolized by R.

14

alkynes

hydrocarbons containing one or more C///C triple bonds

15

amide

an acid derivative that contains a nitrogen atom instead of the hydroxyl group of the acid

16

amine

an alkylated analogue of ammonia; R-NH2, R2NH, or R3N

17

aromatic hydrocarbons

hydrocarbons containing a benzene ring, a six membered ring with three double bonds

18

carbonyl group

the >C=O functional group, as in a ketone or aldehyde

19

carboxyl group

the -COOH functional group, as in a carboxylic acid

20

carboxylic acid

a compound that contains the carboxyl group, -COOH

21

cis-trans isomers

(geometric isomers) stereoisomers that differ in their cis-trans arrangement on a double bond or on a ring. The cis isomer has similar groups on the same side, and the trans isomer has similar groups on opposite sides

22

constitutional isomers

(structural isomers) isomers whose atoms are connected differently; they differ in their bonding sequence

23

cyano group

the -C///N functional group, as in a nitrile

24

dipole-dipole forces

attractive intermolecular forces resulting from the attraction of the positive and negative ends of the permanent dipole moments of polar molecules.

25

ester

an acid derivative with an alkyl group replacing the acid proton

26

ether

a compound with an oxygen bonded between two alkyl (or atomatic) groups

R-O-R'

27

functional group

the reactive, non alkane part of an organic molecule

28

hydrocarbons

compounds composed exclusively of carbon and hydrogen

29

cycloalkanes, cycloalkenes, cycloalkynes

alkanes, alkenes, and alkynes in the form of a ring

30

aromatic hydrocarbons

hydrocarbons containing a benzine ring, a six-membered ring with three double bonds

31

hydroxyl group

the -OH functional group, as in an alcohol

32

ketone

a carbonyl group with two alkyl groups attached

33

nitrile

a compound containing a cyano group, -C///N

34

node

in an orbital, a region of space with zero electron density

35

stereochemistry

the study of the structure and chemistry of stereoisomers

36

stereoisomers

isomers that differ only in how their atoms are oriented in space

37

structural isomers

(constitutional isomers) isomers whose atoms are connected differently; they differ in their bonding sequence

38

bridged bicyclic compound

a compound containing two rings joined at nonadjacent carbon atoms

39

chair-chair interconversion

The process of one chair conformation of a cychlohexane flipping into another one, with all the axial and equatorial positions reversed. The boat (or twist boat) conformation is an intermediate for the chair-chair interconversion,

40

cis

isomers having two similar groups directed toward the same face of a ring or double bond

41

trans

isomers having two similar groups directed toward opposite faces of a ring or double bond

42

combustion

rapid oxidation at high temperatures in the presence of air or oxygen

43

conformational analysis

the study of energetics of different conformations

44

conformations and conformers

Structures that are related by rotations about single bonds. strictly speaking, a conformer is a conformation that corresponds to a relative minimum in energy, usually a staggered conformation. In most cases, conformations and conformers interconvert at room temperature, and they are not true isomers.

45

4 conformations of cyclohexanes

chair

half chair

boat

twisted boat

46

chair conformation

the most stable conformation of cyclohexane, with one part puckered upward and another part puckered downward

47

boat conformation

The less stable puckered conformation of cyclohexane, with both parts puckered upward. The most stable boat is actually the twisted boat conformation. Twisting minimizes torsional strain and steric strain.

48

half-chair conformation

the unstable conformation half way between the chair conformation and boat conformation

49

constitutional isomers

(structural isomers) isomers whose atoms are connected differently; they differ in their bonding sequence

50

eclipsed conformation

any conformation with bonds directly lined up with each other, one behind the other, in the Newman projection

51

fused ring system

a molecule in which two or more rings share two adjacent carbon atoms

52

gauche conformation

a conformation with a 60 degree dihedral angle between the largest groups

53

halogenation

the reaction of alkanes with halogen, in the presence of heat or light, to give products with halogen atoms substituted for hydrogen atoms

54

heat of combustion

the heat given off when a mole of a compound is burned with excess oxygen to give CO2 and H20 in a bomb calorimeter. A measure of energy content of a molecule.

55

homologs

two compounds that differ only by one or more -CH2- groups

56

hydrophilic

attracted to water, soluble in water

57

hydrophobic

repelled by water, insoluble in water

58

methine group

the -CH-group

59

methylene group

the -CH2- group

60

methyl group

the -CH3 group

61

n-alkane, normal alkane, or straight chain alkane

an alkane with all its carbon atoms in a single chain, with no branching or alkyl subsituents

62

newman projections

a way of drawing the conformations of a molecule by looking straight down the bond connecting two carbon atoms

63

paraffins

another term for alkanes

64

ring strain

the extra strain associated with the cyclic structure of a compound, as compared with a similar acyclic compound; composed of angle strain and torsional strain

65

angle strain or torsional strain

the strain associated with distorting bond angles to smaller (or larger) angles

66

saturated

having no double or triple bonds

67

sawhorse structures

the way of picturing conformations by looking down at an angle toward the carbon-carbon bond

68

skew conformation

any conformation that is not precisely staggered or eclipsed

69

spirocyclic componds

bicyclic compounds in which the two rings share only one carbon atom

70

staggered conformation

any conformation with the bonds equally spaced in the newman projection

71

steric strain

the interference between two bulky groups that are so close together that their electron clouds experience repulsion

72

substituent

a side chain or appendage on the main chain

73

IUPAC

International Union of Pure and Applied Chemistry

74

torsional energy or conformational energy

the energy required to twist a bond into a specific confrmation

75

torsional strain

the resistance to twisting about a bond

76

totally eclipsed conformation

a conformation with a 0 degree dihedral angle between the largest groups; usually the highest energy conformation

77

carbanion

A strongly neucleophilic species with a negatively charged carbon atom having only three bonds. The carbon atom has a nonbonding pair of electrons.

78

carbene

A highly reactive species with only two bonds to an uncharged carbon atom with a nonbonding pair of electrons. The simplest carbene is methylene, :CH2

79

carbocation

(carbonium ion, carbenium ion) A strongly electrophilic species with a positively charged carbon atom having only three bonds.

80

catalyst

a substance that increases the rate of reaction by lowering Ea without being consumed in the reaction

81

chain reaction

a multistep reaction where a reactive intermediate formed in one step brings about a second step that generates the intermediate needed for the following step

82

initiation step

the preliminary step in a chain reaction, where the reactive intermediate is first formed

83

propagation steps

the steps in a chain reaction that are repeated over and over to form the product. the sum of the propagation steps should give the net reaction.

84

termination steps

any steps where a reactive intermediate is consumed without another one being generated

85

enthalpy

(heat content, H) A measure of the heat energy in a system. In a reaction, the heat absorbed or evolved is called the heat of a reaction. A decrease in enthalpy is favorable for a reaction (-delta H)

86

endothermic

consuming heat

87

exothermic

giving off heat

88

entropy

the amount of disorder or freedom of motion. an increase in entropy is favorable for a reaction

89

equilibrium

a state of a system such that no more net change is taking place; the rate of the forward reaction equals the rate of the reverse reaction

90

halogenation

the reaction of a halogen or halogen containing reagent that incorporates one or more halogen atoms into a molecule.

91

Hammond Postulate

Related species (on a reaction-energy diagram) that are closer in energy are also closer in structure. In an exothermic reaction, the transition state is closer to the reactants in energy and in structure. In an endothermic reaction, the transition state is closer to the products in energy and in structure.

92

heterolytic cleavage

(ionic cleavage) The breaking of a bond in such a way that one of the atoms retains both of the bonds electrons. Forms two ions.

93

homolytic cleavage

(radical cleavage) The breaking of a bond in such a way that each atom retains one of the bonds two electrons. Produces two radicals.

94

inductive effect

A donation (withdrawal) of electron density through sigma bonds

95

intermediate

A molecule or fragment of a molecule that is formed in a reaction and exists for a finite length of time before it reacts in the next step. Corresponds to a relative minimum low point in the reaction-energy diagram.

96

reactive intermediate

a short lived species that is never present in high concentration because it reacts as quickly as it is formed

97

kinetics

the study of reaction rates

98

mechanism

A step by step pathway from reactions to products, showing which bonds break and which bonds form in what order. The mechanism should include the structures of all intermediates and curved arrows to show the movement of electrons.

99

radical

A highly reactive species in which one of the atoms has an odd number of electrons. Most commonly, a radical contains a carbon atom with three bonds and an "odd" unpaired electron.

100

radical inhibitor

A compound added to prevent the propagation of free radical chain reactions. In most cases, the inhibitor reacts to form a radical that is too stable to propagate the chain.

101

rate limiting step

the slowest step in a multistep sequence of reactions

has the highest energy transition state

102

reaction energy diagram

a plot of potential energy changes as the reactants are converted to products

the vertical axis is potential energy and the horizontal axis is the reaction coordinate, a measure of the progress of the reaction

103

resonance stabilization

stabilization that takes place by delocalization of electrons in a pi bonded system

cations, radicals and anions are often stabilized by resonance delocalization

104

substitution

a reaction in which one atom replaces another, usually as a substituent on a carbon atom

105

termination reaction

a step that produces fewer reactive intermediates (usually free radicals) than it consumes

106

thermodynamics

the study of energy changes accompanying chemical transformations.

thermodynamics is generally concerned with systems at equilibrium

107

transition state

the state of highest energy between reactants and products

a relative maximum high point on the reaction energy diagram

108

absolute configuration

The detailed stereochemical picture of a molecule, including how the atoms are arranged in space.

Alternatively, the R or S conformation of each asymmetric carbon atom.

109

achiral

not chiral

110

allenes

compounds having two C=C double bonds that meet at a single carbon atom, C=C=C

the two outer carbon atoms are trigonal planar, with their planes perpendicular to each other

111

asymmetric carbon atom

a carbon atom that is bonded to four different groups

112

chiral

different from its mirror image

113

chiral carbon atom

asymmetric carbon atom

a carbon atom that is bonded to four different groups

114

chirality center

the IUPAC term for an atom holding a set of ligands in a spatial arrangement that is not superimposable on its mirror image.

asymmetric carbon atoms are the most common chirality centers

115

chiral probe

a molecule or an object that is chiral and can use its own chirality to differentiate between mirror images

116

cis

on the same side of the ring or double bond

117

cis-trans isomers

geometric isomers

isomers that differ in their geometric arrangement on a ring or double bond

a subclass of diastereomers

118

configurations

two possible spatial arrangements around a chirality center or other stereocenter

119

confromers

conformational isomers

structures that differ only by rotations about single bonds

interconvert at room temperature thus they are not different compounds and not true isomers

120

constitutional isomers

structural isomers

isomers that differ in the order in which their atoms are bonded together

121

diastereomers

stereoisomers that are not mirror images

122

enantiomers

a pair of nonsuperimposable mirror image molecules

mirror image isomers

123

Fischer Projection

a method for drawing an asymmetric carbon atom as a cross

the carbon chain is kept along the vertical, with the IUPAC numbering from top to bottom

vertical bonds project away from the viewer, and horizontal bonds project toward the viewer

124

internal mirror plane

a plane of symmetry through the middle of a molecule, dividing the molecule into two mirror image halves

a molecule with an internal mirror plane of symmetry cannot be chiral

125

isomers

different compounds with the same molecular formula

126

meso compound

an achiral compound that contains chirality centers

127

optical isomers

enantiomers

compounds with identical properties except for the direction in which they rotate polarized light

128

optical activity

rotation of the plane of polarized light

129

optically active

capable of rotating the plane of polarized light

130

plane polarized light

light composed of waves that vibrate only in one plane

131

polarimeter

an instrument that measures the rotation of plane polarized light by an optically active compound

132

racemic mixture

a mixture of equal quantities of enantiomers, such that the mixture is optically inactive

133

relative configuration

the experimentally determined relationship between the configurations of two molecules, even though the absolute configuration of either may not be known

134

resolution

the process of separating a racemic mixture into the pure enantiomers

135

resolving agent

a chiral compound used for separating enantiomers

136

stereochemistry

the study of the three dimensional structure of molecules

137

stereoisomers

configurational isomers

isomers whose atoms are bonded together in the same order but differ in how the atoms are oriented in space

138

structural isomers

constitutional isomers

isomers that differ in the order in which their atoms are bonded together

139

alkyl halide

a derivative of an alkene in which one or more of the hydrogen atoms has been replaced by a halogen

140

alkyl shift

movement of an alkyl group with a pair of electrons from one atom (usually carbon) to another

convert carbocations into more stable carbocations

141

allylic

the saturated position adjacent to a carbon-carbon double bond

142

allylic halogenation

substitution of a halogen for a hydrogen at the allylic position

143

aprotic solvent

a solvent that has no acidic protons

a solvent with no O-H or N-H groups

144

dehydrohalogenation

an elimination in which the breaking of bonds and the formation of new bonds occur at the same time in one step

145

electrophile

lewis acid

a species that can accept an electron pair from a nucleophile, forming a bond

146

electrophilicity

electrophile strength

the kinetic reactivity of an electrophile

147

elimination

a reaction that involves the loss of two atoms or groups from the substrate, usually resulting in the formation of a pi bond

148

E1 reaction

multistep elimination where the leaving group is lost in a slow ionization step, then a proton is lost in a second step

Zaitsev orientation is generally preferred

149

E2 reaction

a concerted elimination involving a transition state where the base is abstracting a proton at the same time that the leaving group is leaving

the anti-coplanar transition state is generally preferred

Zaitsev orientation is usually preferred unless the base or the leaving group is unusually bulky

150

hydride shift

movement of a hydrogen atom with a pair of electrons from one atom to another

rearrangements that convert carbocations into more stable carbocations

151

hydroxylic solvent

a solvent containing OH groups (the most common type of protolytic solvents)

152

inversion of configuration

a process in which groups around an asymmetric carbon atom are changed to the opposite spatial configuration, usually as a result of back side attack

153

leaving group

the atom or group of atoms that departs during a substitution or elimination

can be charged or uncharged, but it leaves with the pair of electrons that originally bonded the group to the remainder of the molecule

154

methyl shift

rearrangement of a methyl group with a pair of electrons from one atom (usually carbon) to another

results in a more stable carbocation

155

nucleophile

lewis base

an electron rich species that can donate a pair of electrons to form a bond

156

nucleophilicity

nucleophile strength

the kinetic reactivity of a nucleophile

a measure of the rate of substitution in a reaction with standard substrate

157

nucleophilic substitution

a reaction where a nucleophile replaces another group or atom (the leaving group) in a molecule

158

organic synthesis

the preparation of desired organic compounds from readily available starting materials

159

polarizable

having electrons that are easily displaced toward a positive charge

polarizable atoms can begin to form a bond at a relatively long distance

160

primary halide

if the halogen-bearing carbon atom is bonded to another carbon

161

secondary halide

if the halogen-bearing carbon atom is bonded to two carbons

162

tertiary halide

if the halogen-bearing carbon atom is bonded to three carbons

163

protic solvent

a solvent containing acidic protons, usually O-H or N-H groups

164

racemization

the loss of optical activity that occurs when a reaction shows neither clean retention of configuration nor clean inversion of configuration

165

reagent

the compound that serves as the attacking species in a reaction

166

rearrangement

a reaction involving a change in the bonding sequence within a molecule

common in reactions such as the SN1 and E1 involving carbocation intermediates

167

steric hindrance

interference by bulky groups that slow a reaction or prevent it from occuring

168

substitution

a reaction in which an attacking species (nucleophile, electrophile, or free radical) replaces another group

169

SN2 reaction

the concerted displacement of one nucleophile by another on an sp3 hybrid carbon atom

170

SN1 reaction

a two step interchange of nucleophiles, with bond breaking preceding bond formation

the first step is ionization to form a carbocation

the second step is the reaction of the carbocation with the nucleophile

171

substrate

the compound that is attacked by the reagent

172

syn

adding to (or eliminating from) the same face of a molecule

173

transition state

in each individual step reaction, the state of highest energy between reactants and products

a relative maximum (high point) on the reaction-energy diagram

174

Zaitsev's rule

an elimination usually gives off the most substituted alkene product

gives Zaitsev's orientation

175

dehydrohalogenation

the elimination of a hydrogen halide from a compound, usually base promoted

176

geminial dihalide

a compound with two halogen atoms on the same carbon atom

177

Hofmann product

the least highly substituted alkene product

178

hydrogenation

addition of a hydrogen to a molecule

179

polymer

a substance of high molecular weight made by linking many small molecules, called monomers

180

saturated

having only single bonds; incapable of undergoing addition reactions

181

unsaturated

having multiple bonds that can undergo addition reactions

182

vicinal dihalide

a compound with two halogens on adjacent carbon atoms

183

vinyl group

an ethenyl grop, CH2=CH-

184

Zaitsev's rule

an elimination usually gives the most stable alkene product, commonly the most substituted alkene

doesn't always apply, especially with a bulky base or a bulky leaving group

185

Zaitsev elimination

an elimination that gives the Zaitsev product

186

Zaitsev product

The most substituted alkene product

187

addition

a reaction involving an increase in the number of groups attached to the alkene and a decrease in the number of elements of unsaturation

188

anti addition

an addition in which two groups add to opposite faces of the double bond (as in addition of Br2)

189

electrophilic addition

an addition in which the electrophile bonds to one of the double bonded carbons first, followed by the nucleophile

190

syn addition

an addition in which two groups add to the same face of the double bond

191

alkoxy group

an alkyl group bonded through an oxygen atom, as in ether

192

carbene

a reactive intermediate with a neutral carbon atom having only two bonds and two nonbonding electrons

methylene (:CH2) is the simplest carbene

193

demuercuration

the removal of a mercury species from a molecule

usually accomplished using sodium borohydride

194

glycol

a 1, 2 diol

195

halogenation

addition of a halogen (X2) to a molecule, or the free radical substitution of a halogen for a hydrogen

196

hydroboration

the addition of borane (BH3) to a molecule

197

hydrogenation

the addition of hydrogen to a molecule

198

Markovnikov's rule

when a proton acid adds to the double bond of an alkene, the proton bonds to the carbon atom that already has more hydrogen atoms

in an electrophilic addition to an alkene, the electrophile adds in such a way as to generate the most stable intermediate

199

monomer

one of the small molecules that bond together to form a polymer

200

organic synthesis

the preparation of desired organic compounds from readily available materials

201

oxidative cleavage

the cleavage of carbon-carbon bond through oxidation

202

ozonolysis

the use of ozone, usually followed by reduction, to cleave a double bond

203

peroxide effect

the reversal of orientation of HBr addition to alkenes in the presence of peroxides

204

acetylene

the simplest alkyne, H-C///C-H

also an alkene, a generic term for a compound containing a C///C triple bond

205

acetylide ion

the anionic salt of a terminal alkyne

206

amyl

an older common name for a pentyl

207

enol

an alcohol with the hydroxyl group bonded to a carbon atom of a carbon-carbon double bond

most are unstable, spontaneously isomerizing to their carbonyl tautomers, called the keto form of the compound

208

Lindlar's catalyst

a heterogenous catalyst for the hydrogenation of alkynes to cis alkenes

209

vinyl cation

a cation with a positive charge on one of the carbon atoms of a C=C double bond

generated by the addition of an electrophile to a carbon-carbon triple bond

210

acid derivatives

compounds that are related to carboxylic acids but have other electron-withdrawing groups in place of the -OH group of the acid

211

alcohol

a compound in which a hydrogen atom of a hydrocarbon has been replaced by a hydroxyl group, -OH

classified as primary, secondary, or tertiary depending on whether the hydroxyl group is bonded to a primary, secondary, or tertiary carbon atom

212

aldehyde

a carbonyl compound with one alkyl group and one hydrogen on the carbonyl group

213

formaldehyde

a carbonyl compound with one alkyl group and two hydrogens on the carbonyl group

214

alkoxide ion

the anion (R-O-) formed by the deprotonation of an alcohol

215

azeotrope

a mixture of two or more liquids that distills at a constant temperature and gives a distillate of definite composition

a mixture of 95% ethanol and 5% water has a lower boiling point than pure ethanol or pure water

216

carbinol carbon atom

in the alcohol, the carbon atom bonded to the hydroxyl group

217

denatured alcohol

a form of ethanol containing toxic impurities, making it unfit for drinking

218

diol

a compound with two alcohol -OH groups

219

disulfide

the oxidized dimer of a thiol, R-S-S-R

220

epoxides

compounds containing oxygen in a three membered ring

221

ester

an acid derivative in which the hydroxyl group of the carboxylic acid is replaced by an alkoxy (-OR') group

222

glycol

synonymous with diol

most commonly applied to 1, 2 diols

223

grain alcohol

ethanol, ethyl alcohol

224

Gringnard reagent

an organomagnesium halide, written in the form R-Mg-X

the actual reagent is more complicated in structure, usually a dimer or trimer complexed with several molecules of ether

225

hydride reagent

a compound of hydrogen with a less electronegative element, so the hydrogen can be donated with its pair of electrons

226

hydrophilic

water loving

227

hydrophobic

water hating

228

hydroxy group

the -OH group, as in an alcohol

hydroxyl

229

ketone

a carbonyl compound with two alkyl groups bonded to the carbonyl group

230

mercaptan

thiol

the sulfur analogue of an alcohol, R-SH

231

miscible

mutually soluble in any proportions

232

organolithium reagent

an organometallic reagent in the form R-Li

233

organometallic componds

compounds containing metal atoms directly bonded to carbon

234

phenol

a compound with a hydroxyl group bonded directly to an aromatic ring

235

Raney nickel

a finely divided nickel/aluminum alloy that has been treated with NaOH to dissolve out most of the aluminum

used as a catalyst for the hydrogenation of ketones and aldehydes to alcohols

236

rubbing alcohol

isopropyl alcohol

237

thiol

mercaptan

the sulfur analogue of the alcohol R-SH

238

thiolate ion

mercaptide

the R-S- anion, formed by deprotonation of a thiol

239

wood alcohol

methanol, methyl alcohol

240

alcohol dehydrogenase (ADH)

an enzyme used by living cells to catalyze the oxidation of ethyl alcohol to acetaldehyde

241

aldehyde dehydrogenase (ALDH)

an enzyme used by living cells to catalyze the oxidation of acettaldehyde to acetic acid

242

alkoxide ion

the anion with structure R-O' bearing the negative charge on oxygen

commonly formed by deprotonating an alcohol

243

chromic acid reagent (H2CrO4)

the solution formed by adding sodium or potassium dichromate (and a small amount of water) to concentrated sulfuric acid

244

chromic acid test

when a primary or secondary alcohol is warmed with the chromic acid reagent, the orange color changes to green or blue

a nonoxidizable compound (such as a tertiary alcohol, a ketone, or an alkane) produces no color change

245

condensation

a reaction that joins two or more molecules, often with the loss of a molecule such as water or an alcohol

246

ester

an acid derivative formed by the reaction of an acid with an alcohol with loss of water

the most common are carboxylic esters, composed of carboxylic acids and alcohols

247

Fischer esterification

the acid catalyzed reaction of an alcohol with a carboxylic acid to form an ester

248

inorganic esters

compounds derived from alcohols and inorganic acids with loss of water

249

ether

a compound containing an oxygen atom bonded to two alkyl or aryl groups

250

glycol

synonymous with diol

251

oxidation

Loss of H2; addition of O or O2; addition of X2 halogens

alternatively, an increase in the number of bonds to oxygen or halogens or a decrease in the number of bonds to hydrogen

252

pinacol rearragement

dehydration of a glycol in which one of the groups migrates to give a ketone

253

reduction

addition of H2; loss of O or O2; loss of X2 halogens

alternatively, a reduction in the number of bonds to oxygen or halogens or an increase in the number of bonds to hydrogen

254

Williamson esther synthesis

the SN2 reaction between an alkoxide ion and a primary alkyl halide or tosylate

the product is an ether