Midterm 2

Question 1

how to synthesize an either

Answer 1

Add NaH and an alkyl halide

Question 2

dehydration of alcohols occurs in … and give two examples

Answer 2

occurs in the presence of strong acid

1) H2SO4
2) TsOH

Question 3

describe the reaction mechanism for dehydration of alcohols

Answer 3

secondary and tertiary mechanism E1

primary E2 mechanism

Question 4

what can we add to convert alcohols to alkyl halides

Answer 4

H-X

ex: H-Br, H-Cl

Question 5

what reaction mechanism can alcohol + H-X be?

Answer 5

SN1 and SN2

Sn1 for 2 and 3 alcohols
Sn2 for methyl and primary alcohols

Question 6

what is special about SOCl2

Answer 6

when added to alcohol you will create alkyl chloride

** ONLY SN2 mechanism –> primary and secondary alcohols
** need pyrimidine with it

Question 7

what is special about PBr3

Answer 7

when added to alcohol you will create alkyl bromide

** ONLY SN2 mechanism
–> primary and seconary alcohols

Question 8

what happens when you add TsCl to an alcohol

Answer 8

*** NEED TsCL and PYRIMIDINE

–> substitution of -Oh for -Ots occurs with retention of stereochemistry

–> can add good nucleophile to the -Ots to have an Sn2 or E2 reaction (depending on the nucleophile)

Question 9

describe a reaction with an either and a strong acid

Answer 9

**CAN occur with Sn1 or SN@

**NEED 2 equivalents of the acid –> H-Br

** creates two alkyl halides

Question 10

what are the two ways to make epoxides and their differences

Answer 10

nucleophile OR acid catalyzed

NU: attacks LEAST SUBSTITUTED Carbon

Acid: attacks more substituted carbon

Question 11

what type of mechanism is the creation of an epoxide

Answer 11

SN2 mechanism ONLY

Question 12

what is hydrohalogenation in alkenes

Answer 12

alkene + H-X

Question 13

describe hydrohalogenation in alkenes

Answer 13

relocations CAN occur

** H-atomes bond to the least substituted carbon

**BOTH SYN AND ANTI addition

Question 14

what is hydration in alkenes

Answer 14

adding H20 and H2SO4 to an alkene –> to create an alcho;

Question 15

describe hydration in alkenees using H20 and H2SO4

Answer 15

h adds to less substituted carbon to form the more stable carbocation

** rearrangements can occur –> SYN and ANTI addition

Question 16

what is halogenation in alkenes

Answer 16

adding an X-X to an alkene –> to create a vicinal dihalide

Question 17

describe halogenation in alkenes using X-X

Answer 17

no rearrangements can occur

ONLY ANTO addition

Question 18

what is halohydrin formation in alkenes

Answer 18

addition of X-x and H20 to an alkene

Question 19

describe halohydrin formation in alkenes

Answer 19

no rearrangements can occur

ONLY ANTI addition
electrophile bonds to the less substituted carbon

Question 20

what is hydroboration in alkenes

Answer 20

addition of BH3 to an alkene

Question 21

describe hydroboration in alkenes

Answer 21

born atom binds to the less substituted carbon

SYN addition
retention of configuration

Question 22

what is hydrohalogenation in alkynes

Answer 22

addition of TWO H-X to an alkyne to create a geminal halide

Question 23

what is halogenation in alkynes

Answer 23

addition of TWO X-X to an alkyne to create two geminal halides

Question 24

what is hydration in alkynes

Answer 24

Adding H2SO4, H20 to create an UNSTABLE enol and then a keto

–> oxygen adds to most substituted carbon

Question 25

what is hydroboration in alkynes

Answer 25

adding Bh3 to an alkyne to create an carbonyl group ** BH2 adds to least sterically hindered carbon

Question 26

how do we deprotonate an Acetylide anion

Answer 26

NEED A strong base usually above 35 like NaNH2 or NaH