Organic Electrophilic Additions

identify the mechanism

electrophilic addition

identify the mechanism

epoxidation

identify the mechanism

carbene addition

identify the mechanism

diels-alder

C=C are BLANK which makes them attractive to BLANK

electron rich, electrophiles

conjugated dienes allow both BLANK and BLANK addition

1,2-, 1,4-

how does 1,2 and 1,4 addition occur on dienes?

via an allylic carbocation

the product of 1,2 or 1,4 addition of a diene is usually a

mixture of both

1,2 products are referred to as

kinetic

1,4 products are referred to as

thermodynamic

1,2 products form BLANK than 1,4

faster

if a diene addition reaction ends prior to equilibrium, which product is in abundance

1,2

if diene addition reaches equilibrium, which product is in abundance

1,4

1,4 products are more BLANK than 1,2 products

stable

epoxidation, carbene addition, and diels-alder are similar in that they

do not involve the formation of an intermediate

Hydroboration oxidation of alkenes almost always results in

anti-Markovnikov regioselectivity (often via syn-addition)

when does hydroboration-oxidation of alkenes not results in anti-markovnikov regioselectivity

symmetrical alkenes, internal alkynes

attempting electrophilic addition of alkenes under acidic conditions causes what to happen to the product

free carbocations that rearrange so rapidly that a singular regioselectivity is not able to be achieved

Oxymercuration-demercuration results in BLANK for unhindered alkenes, by avoiding BLANK

markovnikov regioselectivity (often via anti addition), free carbocations

Identify the orientation

Markovnikov orientation

identify the orientation

anti-markovnikov

identify the mechanism

syn-addition

identify the mechanism

anti-addition

what would a product resulting from syn addition with markovnikov orientation look like for the reaction

what would a product resulting from anti addition with markovnikov orientation look like for the reaction

what would a product resulting from syn addition with anti-markovnikov orientation look like for the reaction

what would a product resulting from anti addition with anti-markovnikov orientation look like for the reaction

according to markovnikov’s rules, the nucleophile will add to the carbon that can form the

most stable carbocation intermediate

the addition of bromine to an alkene occurs via BLANK forming at BLANK

anti-addition, either the top or the bottom of the double bond

the stereochemistry of the alkene in an epoxidation reaction

is maintained in the epoxide

the oxymercuration-demercuration of alkynes will always result in a

ketone (enol intermediate)

the stereochemistry of an alkene in a diels alder reaction

is maintained in the resulting 6 membered ring

the preferred transition state of diels alder reaction leads to a stereoisomer in which the unsaturated substituent is BLANK

endo (trans to the carbon bridge)

exo orientation in a diels alder reaction is BLANK but its transition state energy is BLANK so it is BLANK to form than endo

more stable, higher, slower

bromine addition to alkenes proceeds thorugh an

intermediate bromonium ion

when a solvent is not nucleophilic in bromine addition to alkene, what nucleophile(s) is present

the bromide counter ion

when the solvent is nucleophilic in bromine addition to alkene, the solvent nucleophile can

attack the bromonium ion to form a beta-bromoether

in bromine addition to an alkene, since the solvent is in large excess over the bromide ion the nucleophilic attack by the solvent

predominates

alpha-carbons

carbon directly next to the functional group

beta-carbons

the carbon one carbon seperated from the functional group