methyl acetoacetate unit.Thea,bunsaturated aldehyde 4 was en-
visaged to be synthesized via functionalization of diketoalcohol 5 as
follows: stereoselective reduction of the C1-ketone (pyripyropene
A numbering), oxidation of the alkene, and one-carbon elongation
of another ketone. The trans-fused decaline unit of 5 could be
constructed by the Ti(III)-mediated radical cyclization of 6. The
epoxide 6 should be available from a commercially available (R)-
carvone.