Synthesis and Pseudomonas Lipase Inhibition Study of Stereoisomers of Decahydro-2-naphthyl-N-n-butylcarbamate

(2S,4aR,8aS)-Cis,cis-, (2R,4aS,8aR)-cis,cis-, rac-cis,cis-, and rac-trans,cis-decahydro-2-naphthyl-N-n-butylcarbamates are synthesized from condensation of (2S,4aR,8aS)-cis,cis-, (2R,4aS,8aR)-cis,cis-, rac-cis,cis-, and rac-trans,cisdecahydro- 2-naphthols, respectively, with n-butyl isocyanate in the presence of triethylamine in dichloromethane. Optically pure (2S,4aR,8aS)-(-)- and (2R,4aS,8aR)-(+)-cis,cis-decahydro-2-naphthols are resolved by the porcine pancreatic lipase- catalyzed acetylation of decahydro-2-naphthols with vinyl acetate in t-butyl methyl ether. Absolute configurations of (2S,4aR,8aS)-(-)- and (2R,4aS,8aR)-(+)- cis,cis-decahydro-2-naphthols are determined from the 19F NMR spectra of their Mosher's ester derivatives. (2S,4aR,8aR)-Trans,cis- and (2R,4aS,8aS)-trans,cis-decahydro-2-naphthols can't be resolved from the porcine pancreatic lipase-catalyzed acetylation of decahydro-2-naphthols with vinyl acetate in t-butyl methyl ether. For the inhibitory potency of Pseudomonas lipase, (2S,4aR,8aS)-cis,cis-decahydro-2-naphthyl-N-n-butylcarbamate is 3.5 times more potent than (2R,4aS,8aR)-cis,cis-decahydro-2-naphthyl-N-n-butylcarbamate; racemic cis,cis-decahydro- 2-naphthyl-N-n-butylcarbamate is about the same with trans,cis-decahydro-2-naphthyl-N-n-butylcarbamate. These inhibitors also show similar effects on porcine pancreatic lipase.