Ch 9 Reactions

Question 1

Terminal Alkyne –> Acetylide

Answer 1

NaNH2 or nBuLi

Question 2

Terminal Alkyne –> Primary Alcohol

Answer 2

1) Acetylide anion 2) React with formaldehyde

Question 3

Terminal Alkyne –> Secondary Alcohol

Answer 3

1) Acetylide anion 2) React with aldehyde

Question 4

Terminal Alkyne –> Tertiary Alcohol

Answer 4

1) Acetylide anion 2) React with ketone

Question 5

Terminal Alkyne –> Internal alkyne

Answer 5

1) Acetylide anion 2) React with alkyl halide or similar

Question 6

Terminal alkyne –> Alkene (E2)

Answer 6

1) Acetylide anion 2) React with sterically hindered substrate

Question 7

Alkyne –> Alkane

Answer 7

Catalytic hydrogenation

Question 8

Alkyne –> cis alkene (1)

Answer 8

H2 + Nickel boride

Question 9

Alkyne –> cis alkene (2)

Answer 9

H2, Pd/BaSO4, Quinoline, CH3OH

Question 10

Alkyne –> trans alkene

Answer 10

Birch Reduction: Na (s), NH3(l), -33C

Question 11

Internal alkyne –> Dihalogenated alkene

Answer 11

1 eq X2

Question 12

Internal alkyne –> Tetrahalogenated alkane

Answer 12

> 1 eq X2 (REMEMBER TO INCLUDE TRANSITION STATE)

Question 13

Terminal alkyne –> Halogenated alkene

Answer 13

1 eq HX

Question 14

Internal alkyne –> Halogenated alkene (4 products)

Answer 14

1 eq HX

Question 15

Terminal alkyne –> Geminal dihalide

Answer 15

> 1 eq HX

Question 16

Terminal alkyne –> Most substituted enol –> Methyl ketone

Answer 16

1) HgSO4, H2O, H2SO4 2) Acidic keto-enol tautomerism

Question 17

Terminal alkyne –> Least substituted enol –> aldehyde

Answer 17

1) Sia2BH 2) HOOH, NaOH 3) Basic keto-enol tautomerism

Question 18

Alkyne –> Diketone

Answer 18

KMnO4 (cold, dilute), H2O

Question 19

Alkyne –> 2 carboxylates (1)

Answer 19

KMnO4 (conc), KOH, H2O, heat (aqueous wkup –> carboxylic acids). Different products for terminal/internal

Question 20

Alkyne –> 2 carboxylates (2)

Answer 20

O3, H2O. Different products for terminal/internal