Page 305 - Advanced Organic Chemistry Part B - Reactions & Synthesis

Problems 277
PROBLEMS
(References for these problems will be found on page 1275.)

3.1. Give the products that would be expected to be formed under the specified
reaction conditions. Be sure to specify all aspects of the stereochemistry.

(b)
(a) HCl
O C 7 H 13 O 2 Cl EtN(i-Pr) 2
CH 3 CH 2 O CH 3 OH CH 3 (CH 2 ) 4 CH 2 OH + ClCH 2 OCH 3 C 8 H 18 O 2
CH 2 Cl 2
(c)
(d)
(S ) – CH 3 (CH 2 ) 3 CHCH 3 + 1) Ph 3 P, HN 3
C 2 H 5
N Et 3 N C 2 H 5 O 2 CCH 2 CHCO 2 C 2 H 5 C 8 H 13 N 3 O 4
+ 2) DEAD
OH Cl C 6 H 13 Cl
+
O Et 4 N Cl – OH
O
(e)
(f)
N(CPh) 2
CH 3
N +
N (PhO) 3 PCH 3 I – PPh 3
C 38 H 28 N 5 O 7 I C 10 H 17 Cl
N N DMF, 20°C CCl 4
O
HOCH 2
10 min
CH 3 CHCH 2 OH
O 2 CPh
PhCO 2
(h)
C 2 H 5
(g) H
BBr , –78°C CO 2 CH 3
CH 2 CO 2 H 3 C 11 H 12 O 2 H 1) p -toluenesulfonyl chloride
0°C, 1 h Ph C 14 H 12 O 2 S
–
OH 2) PhS Na +
CH Cl 2
OCH 3 2
(j)
(i) HOCH 2 1) CH 3 SO 2 Cl
pyridine
1) NaOH C 16 H 18 S
(C 6 H 5 ) 2 CHBr + P(OCH 3 ) 3 + C 13 H 13 PO 3 2) Na 2 S
2) H
HMPA
HOCH 2
(k) O
(l) H CO 2 H t-BuOH
CH 3 O
48% HBr DCC, C 10 H 16 O 4
C 17 H 17 NO 3 C 2 H 5 O 2 C H DMAP
CH 3 O NCH 2 C 6 H 5 heat
3.2. When (R)-(−)-5-hexen-2-ol was treated with Ph P in refluxing, CCl ,(+)-
3
4
5-chloro-1-hexene was obtained. Conversion of (R)-(−)-5-hexen-2-ol to its
4-bromobenzenesulfonate ester and subsequent reaction with LiCl gave (+)-
5-chloro-1-hexene. Reaction of (S)-(+)-5-hexen-2-ol with PCl in ether gave
5
(−)-5-chloro-1-hexene.
a. Write chemical equations for each of these reactions and specify whether each
occurs with net retention or inversion of configuration.
b. What is the sign of rotation of (R)-5-chloro-1-hexene?
3.3. A careful investigation of the extent of isomeric products formed by reaction of
several alcohols with thionyl chloride has been reported. The product compos-
itions for several of the alcohols are given below. Identify the structural features
that promote isomerization and show how each of the rearranged products is
formed.