Enantioselective total syntheses of the novel tricyclic sesquiterpene hydrocarbons (+)- and (−)-kelsoene. Absolute configuration of the natural product
作者:Goverdhan Mehta、K Srinivas
DOI:10.1016/s0040-4039(01)00288-x
日期:2001.4
lipase-catalysed kinetic resolution of endo,endo–cis-bicyclo[3.3.0]octane-2,6-diol rac-3 has provided ready access to bicyclo[3.3.0]octane-2,6-diones (−)-2 and (+)-2 of high enantiomeric purity. These C2-symmetric diones have been further elaborated to the sesquiterpene hydrocarbon (+)-kelsoene 1 and ent-kelsoene (−)-1, respectively, thereby establishing the absoluteconfiguration of the natural product
An improved procedure for the lipase-catalysed kinetic resolution of endo-endo-cis-bicyclo[3.3.0]octane-2,6-diol—synthesis of potential C2-symmetric enantiomerically pure bidentate auxiliaries
An improved procedure for the kinetic resolution of endo-endo-cis-bicyclo[3.3.0]octane-2,6-diol rac-1 by transesterification with vinyl acetate catalysed by lipase from Pseudomonas cepacia in an organic solvent which yields both enantiomers with an enantiomeric excess of > 95% is described. The configuration at both stereogenic centres bearing hydroxy groups has been inverted by treatment of the corresponding mesylates with caesium acetate in the presence of 18-crown-6 to afford, after deacetylation, the corresponding enantiomerically pure diastereoisomeric exo-exo-cis-diols. (C) 1997 Elsevier Science Ltd.
DJADCHENKO, MARINA A.;PIVNITSKY, KASIMIR K.;THEIL, FRITZ;SCHICK, HANS, J. CHEM. SOC. PERKIN TRANS. PT 1,(1989) N1, C. 2001-2007
作者:DJADCHENKO, MARINA A.、PIVNITSKY, KASIMIR K.、THEIL, FRITZ、SCHICK, HANS