Asymmetric synthesis of the chlorocyclopropane-containing callipeltoside A side chain.
[reaction: see text] The callipeltoside A chlorocyclopropyl-containing dienyne side chain has been synthesized in nine steps and 33% overall yield from commercially available 1,2,5,6-O-dicyclohexylidene-D-mannitol. The key steps in the synthesis are a hig