Abstract
The de novo asymmetric synthesis of cladospolides B and C and
(ent )-cladospolide D has been achieved
from achiral non-1-yne. The 11-13-step route relies upon
a Noyori reduction and a KAPA promoted alkyne zipper reaction to
relay an achiral functionality across a nine-carbon fragment and
to enable the installation of a dienoate functionality. A diastereo-
and regioselective Sharpless dihydroxylation of a dienoate installed
the remaining stereochemistry. The de novo asymmetric route allowed
for the asymmetric synthesis of three members of the cladospolide
natural products and correctly established the structure for cladospolide
D.
Key words
cladospolides B-D - asymmetric synthesis - natural product synthesis -
E/Z -alkene
isomerization
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