10. Addition Reactions

What would the yield be if two more steps (each with an 80% yield) were added to the synthesis?

What reagents should be used to carry out the following syntheses?

α-Pinene is a terpene found in pine trees. Starting from geranyl diphosphate (a terpene), draw the arrow-pushing mechanism to produce α-pinene. Assume that an enzyme active site will provide whatever acids and bases you might need.

What stereoisomers are obtained when 2-butyne undergoes each of the following reaction sequences?

c. 1. Cl₂/CH₂Cl₂ 2. Br₂/CH₂Cl₂

Predict the products you would get when the following alkenes react under the following conditions: (i) H₂SO₄, H₂O and (ii) 1. Hg(OAc)₂, H₂O , 2. NaBH₄

(c)

Drawing on what you know about the stereochemistry of alkene addition reactions,

b. predict the configuration of the product of the reaction.

Predict the product(s) that would result when the alkenes shown here are allowed to react under the following conditions: (i) HBr; (ii) HCl; (iii) HBr, H₂O₂ (iv) H₂SO₄, H₂O (v) 1. Hg(OAc)_2, H₂O 2. NaBH₄ ; (vi) 1. BH₃ 2. H₂O₂, NaOH

(d)

Draw the mechanism for the following reaction:

Predict the products you would get when the following alkenes react under the following conditions: (i) H₂SO₄, H₂O and (ii) 1. Hg(OAc)₂, H₂O , 2. NaBH₄

(d)

Answer Problem 39 , parts a–h, using 2-butyne as the starting material instead of propyne.

d. Br₂ (2 mol)/CH₂Cl₂

For the alkynes shows here, show the product(s) expected to form when treated under the following conditions: (ix) Br₂ (2 equiv.). If you expect two products, show both.

(f)

Show how hex-1-yne might be converted to

d. 1,1,2,2-tetrabromohexane.

Which electrophilic addition reactions

c. form a three-membered ring

What stereoisomers are obtained when 2-butyne undergoes each of the following reaction sequences?

a. 1. H₂/Lindlar catalyst 2. Br₂/CH₂Cl₂

Predict the product(s) that would result when the alkenes shown here are allowed to react under the following conditions: (v) 1. Hg(OAc)₂ , H₂O 2. NaBH₄

(b)