Enzyme‐Mediated Preparation of the Enantiomerically Enriched Isomers of the Odorous Tetrahydropyranyl Acetates Jasmal ® and Jessemal ® , and Their Olfactory Evaluation

All four stereoisomers of the fragrance Jasmal ® of structure 3,4,5,6‐tetrahydro‐3‐pentyl‐2 H‐ pyran‐4‐yl acetate were prepared by enzymatic resolutions of the corresponding alcohols. The absolute configurations were unambiguously determined by comparison with the enantiomer (3 R ,4 S )‐ 1 prepared from L ‐tartaric acid. The four stereoisomers of the fragrance Jessemal ® of structure 3‐butyl‐5‐methyl‐3,4,5,6‐tetrahydro‐2 H‐ pyran‐4‐yl acetate were obtained starting from the epoxy alcohol 10 , which was obtained in an optically pure state by enzymatic resolution of the racemic mixture. The olfactory evaluations of all stereoisomers are reported. 1 H‐NMR Conformational analysis of diastereoisomers (3 RS ,4 RS ,5 RS )‐ 2 and (3 RS ,4 SR ,5 RS )‐ 2 is also reported.