Abstract
The enantioselective preparation of the two diastereoisomeric forms of 2,15-dihydroxycalamele‘ne and 2-methoxycalamenene is here described. The (7S,10R) and (7R,10R) isomers of these natural products were synthesized starting from (5R,8S)-methyl-4-hydroxy-8-isopropyl-5-methyl-5,6,7,8-tetrahydronaphthalene-2-carboxylate and (5R,8R)-methyl-4-hydroxy-8-isopropyl-5-methyl-5,6,7,8-tetrahydronaphthalene-2-carboxylate, respectively, in turn preparable from (-)-menthone and (+)-isomenthone. The NMR analysis of the obtained sesquiterpenes allow assigning (7R,10S) absolute configuration to the natural occurring 2,15-dihydroxycalamelene.
