Preparation and Odor Evaluation of Both Enantiomers of 3,4,4aα,5,6,7,8,8aβ-Octahydro-5,5,8aβ-trimethyl-2(1H)-naphthalenone and 1,2α,3,4,4aβ,5,6,7,8,8aβ-Decahydro-5,5,8aβ-trimethyl-2β-naphthalenyl Acetate,Four Woody Odorants

The enantiomeric decahydro-2-naphthalenols (+)- 5 and (?)-5 were prepared by enantioselective hydrolysis of the racemic chloroacetate (±)- 2 catalyzed by porcine pancreatic lipase, and converted to the corresponding acetates (+)- 1 and (?)- 1 and ketones (+)- 6 and (?)- 6 . The absolute configurations of the ketones, alcohols, and acetates were established by chemical correlation with natural manool ((+)- 7 ) by making use of a retro-ene cleavage reaction of the known manool degradation product 8 to (?)- 6 . A distinct odour difference between the two enantiomers of each pair (+)- 1 /(?)- 1 and (+)- 6 /(?)- 6 has been found.