Page 1289 - Advanced Organic Chemistry Part B - Reactions & Synthesis

13.7. One approach to the synthesis of enantiomerically pure compounds is to start with 1265
an available enantiomerically pure substance and effect the synthesis by a series of
enantiospecific reactions. Devise a sequence of reactions that would be appropriate PROBLEMS
for the following syntheses based on enantiomerically pure starting materials.

(a)
HC OH
C CH 3 from H O CO 2 H
CH 3 H
CH 3

(b) CH 3 CO 2
HO
CH 2 CO 2 CH 3 CO 2 H
from H
CH 2 CO 2 H
CO 2 CH 3
O
(c) CH 3 O 2 C CO 2 H
N CHCH CH 2 H 2 N C H
Ph OH from
S CH 2 SH
CH 2 OH
(d) CH O HO C H
H C OH from HO C H
CH 2 OH H C OH
H C OH
CH 2 OH
(e) H
from
O O CH 3 (CH 2 ) 10 O
CH 3 (CH 2 ) 10

(f) CH 2 OH OH
CH 3
HO OH from O
HO O CH 3 O O
CH 3 CH 3

(g) CH 3
O CH CH 3 O
from
CH 3
O
(CH 3 ) 2 CH
CH(CH 3 ) 2
O
(h) O
H O
from CH 3 H
O H H
CH 3
13.8. Several syntheses of terpenoids are outlined in retrosynthetic form. Suggest a
reagent or short reaction sequence that could accomplish each lettered transfor-
mation in the synthetic direction. The structures refer to racemic material.