Total Syntheses of a Family of Cadinane Sesquiterpenes.

Concise total syntheses of (-)-(1 R,6 S,7 S,10 R)-hydroxycadinan-3-en-5-one (1), (+)-(1 R,5 S,6 R,7 S,10 R)-cadinan-3-ene-1,5-diol (2), and (+)-(1 R,5 S,6 R,7 S,10 R)-cadinan-4(11)-ene-1,5-diol (3), three cadinane sesquiterpenes sharing identical trans-decalin carbon skeletons yet containing different oxidation states and substitution patterns, are reported. They were prepared from a common trans-decalin intermediate, which was readily prepared on gram scale through an aldol-Henry reaction cascade and oxidation sequence.