134
4. Nitrogenous Compounds
For the synthesis of nereistoxin (52) Hagiwara et al. (1965) reacted 1,3dichloro-2-propanol (56) with sodium benzylmercaptide (57) to yield 1,3bis(benzylthio)-2-propanol (58). Treatment of 58 with thionyl chloride led to
a mixture of the normal (and hoped-for) substitution product 59a and an
(unexpected) rearranged isomer 60a. The structures of 59a and 60a were
proven by spectral data and by further chemical transformations. The
unseparated mixture of 59a and 60a was heated under pressure with dimethylamine in benzene and furnished a mixture of the corresponding dimethylamino derivatives 59b and 60b. The asymmetrical (and undesired) compound 60b was the major product, which could be isolated and crystallized
as the hydrogen oxalate salt. Identity of the minor amine 59b was secured
by chromatographic comparison with a degradation product of nereistoxin.
Birch reduction of the mixed amines 59b and 60b led to a mixture of amine
dithiols (61 and 62), which was readily separable since the symmetrical
CH 2 C1
CH 2 —SCH 2 - /
/
HO—CH
+ NaSCH 2 -^
• HO—CH
X CH 2 C1
X
CH 2 —SCH 2 -^
56
57
58
1. SOCI 2
2. HNMe a
R
^
I
CH
CH 2 —CH—CH 2 R
/
\
II
CH 2 CH 2 + S
S
II
II
S
S
CH 2 ^ CH 2 ^
ι
ι
CH 2 ^ CH 2 ^
59
60
a: R = Cl
b: R = NMe 2
Na/NH 3
NMe 2
?
M e 2
1
C
H
CH 2 —CH—CH 2 NMe 2
<
>
ο
/
\
1
1
\
/ 4r2*— CH 2
CH 2
+ SH
SH
s—s
I
I
SH
SH
52
61
62
SCHEME 4.1