A Partial Synthesis of (-)-Shinjulactone H from (+)-Quassin

Article abstract of DOI:10.1021/jo00034a008

A partial synthesis of (-)-shinjulactone H (3) from (+)-quassin (1) required the selective manipulation of two similar O-methyldiosphenol groups.Protection of the δ-lactone in 1 as an ortho ester, selective reduction of the C-1 carbonyl group, hydrolysis of the resulting enol ether in the A ring, and catalytic hydrogenation of the O-methyldiosphenol in the C ring delivered an intermediate possessing an α-ketol group in the A ring and an α-methoxy ketone group in the C ring.Demethylation and concomitant α-ketol tautomerization in the A ring delivered (-)-shinjulactone H (3).