Page 10 - Volume 3, Issue 2, July 2010
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© Benaki Phytopathological Institute
Mihou & Michaelakis
40
three simple transformations: i) elongation
at C-5 position by oxidation and Wittig olefi-
nation, ii) reductive cleavage of the C-4 car-
bon with magnesium in methanol, iii) intro-
duction of the long chain at C-1 of
D
-ribose
by Wittig reaction. The olefin produced was
hydrogenated to give the desired methyl es-
ter. Further basic hydrolysis of the ester af-
forded the known acid
13
, which could be
easily transformed to the desired phero-
mone by simple manipulations according
to literature (Kang and Cho, 1989) (Figure 8)
(7steps, 11.8% overall yield)
.
Wu (1991) published the synthesis of
1a
from
D
-glucose. 2,3-
O
-Ethylidene-
D
-eryth-
rose, easily prepared as an anomeric mix-
ture in three steps from
D
-glucose, was
treated with triphenylnonylphosphorane to
afford a mixture of alkenes,
15
. Subsequent
oxidation, Wittig reaction of the produced
aldehyde, hydrogenation of the two dou-
ble bonds, deprotection, acid lactonization
and finally acetylation furnished the natural
pheromone (Figure 9).
The stereoselective synthesis of (–)-(5
R
,
6
S
)-6-acetoxy-5-hexadecanolide from the
readily available chiral pool compound,
L
-
(+)-tartaric acid was accomplished by Prasad
(Prasad and Anbarasan, 2007b) (Figure 10).
The synthetic sequence includes the elabora-
tion of an
α
-benzyloxy aldehyde,
18
, derived
from tartaric acid with ring closing metath-
Figure 9
Figure 8
