A short and highly stereoselective synthesis of the naturally
occurring, α,β-unsaturated lactone synargentolide
A is described from the chiral starting material 3,4,6-tri-O-acetyl-d-glucal. Key
steps of the synthesis are lactol opening, Brown’s asymmetric allylation,
and a ring-closing metathesis (RCM) reaction.
3,4,6-tri-O-acetyl-d-glucal - δ-lactones - synargentolide - Brown’s
allylation - RCM
