h

Syn addition

Two groups added to the same face of alkene

Anti addition

Two groups added to opposite faces of alkene

HBr addition

syn and anti (random)

acid-catalyzed hydration

syn and anti (random)

Bromination/bromohydrin formation

anti addition

oxymercuration reduction

anti addition (only for first step)

Pd-catalyzed hydrogenation

syn addition

hydroboration/oxidation

syn addition

methylene chloride

CH2Cl2

butyl bromide

CH3CH2CH2CH2—Br

isopropyl iodide

(CH3)2CH—I

allyl chloride

H2C=CH—CH2—Cl

benzyl group

Ph—CH2—

HCCl3

Chloroform

HCBr3

Bromoform

HCI3

Iodoform

alpha-carbon

Carbon bonded to the halogen or oxygen

methoxy and methylthio

Furan

Tetrahydrofuran

Thiophene

Dioxane

Oxirane

non-polar solvents

alkanes, benzene, diethyl ether, toluene

moderately polar solvents

THF, ethyl acetate, chloroform, methylene chloride

polar solvents

Sn2 mechanism

leaving group: I>Br>Cl

E2 mechanism

must be anti

Strong Nucleophile and Strong Base

Sn2 and E2: NaOH, NaOMe, NaOEt

Strong Nucleophile but weak base

Sn2: NaN3, NaCN, NaSPh, NaI, NaBr

Weak nucleophile but strong base

E2: NaOtBu (RMgBr and RLi)

Weak nucleophile and weak base

Sn1 and E1: NaF, NaCl, ROH, H2O, CH3COONa

Sn1 and E1 mechanism

most rapid with tertiary, slower with secondary, never with primary, C+ chift to more stable position

Carbene mechanism

Simmons smith Rx

CH2I2 with Zn-Cu couple