Chapter 7 - Alkenes and Alkynes

Question 1

Hydrohalogenation across an alkene

Answer 1

Question 2

Markovnikov Product

Answer 2

H will go to carbon with more H’s on it, and the other substituent will go on the carbon with fewer H’s on it

Question 3

List carbocation stability from greatest to least

Answer 3

Question 4

Which types of reactions will add OH or OR to alkenes?

Answer 4

acid catalyzed hydration

oxymercuration - demercuration

acid catalyzed alcohol addition

Question 5

Describe what is added, regioselectivity, and whether a rearrangement is possible in acid catalyzed hydration

Answer 5

Question 6

Describe what is added, regioselectivity, stereoselectivity, and whether a rearrangement is possible in oxymercuration-demercuration

Answer 6

Question 7

Describe what is added, regioselectivity, and whether a rearrangement is possible in acid catalyzed alcohol addition

Answer 7

Question 8

Adding a halogen across an alkene will have what type of stereoselectivity?

Answer 8

anti

Question 9

T/F? Rearrangements when adding halogens across a double bond are not possible.

Answer 9

true

Question 10

What will give products in anti-markovnikov fashion when doing reactions with alkenes?

Answer 10

hydroboration-oxidation and hydrobromination with peroxide

Question 11

In hydroboration-oxidation, the product will have ____ stereoselectivity

Answer 11

syn

Question 12

When adding nucleophiles to an epoxide under acidic conditions, attack will occur at the ____ ___ position.

In basic conditions, it will attack at the most ___ ____ position

What type of stereoselectivity will it have?

Answer 12

acidic = most substituted

basic = least substituted anti

syn

Question 13

In ozonolysis, a workup containing Zn, water, or (CH3)2S will form what kind of product?

If a workup contained just H202, what will the product look like?

Answer 13

Zn, H2O, (CH3)2S = one oxygen per carbon

H2O2 = one OH will replace one H

Question 14

In catalytic hydration of alkenes, describe which reagent is used to create an E alkene or a Z alkene

Answer 14

E = Na or Li, with NH3

Z = H2 and lindlar catalyst

*E and Z are referring to the H’s being on the opposite or same sides, respectively

Question 15

Differentiate between hydrohalogenation of terminal vs. internal alkynes

Answer 15

terminal - addition of HX markovnikov style

internal - two products

Question 16

Describe the product of di-halogenation of an alkyne with one equivalent of the halogen, then with excess.

Answer 16

one equivalent - alkene with E addition of the halogen

excess - tetra halide

Question 17

Acid catalyzed hydration of an alkyne will form what kind of product?

Answer 17

enol - will tautomerize to form a ketone

Question 18

If an alkyne underwent a hydration through hydroboration-oxidation, what product will form?

How about if the same alkyne underwent an acid catalyzed hydration reaction?

Answer 18

hydroboration-oxidation = antimarkovnikov enol, which will tautomerize to an aldehyde

acid catalyzed hydration = markovnikov enole, which will tautomerize to a ketone

Question 19

Alkylation of an alkyne uses ____ as a reagent, which will do nucleophilic attack on a terminal alkyne to create a ______

Answer 19

NaNH2, acetylide