The Total Synthesis of (±)-Isocomene by an Intramolecular Ene Reaction. Preliminary communication
作者:Wolfgang Oppolzer、Kurt Bättig、Tomas Hudlicky
DOI:10.1002/hlca.19790620514
日期:1979.7.17
The racemic sesquiterpene isocomene (1) has been synthesized starting from 1,7-octadien-3-one (2) in a stereoselective manner (Scheme 2). In the key step 4 5 the C(7), C(8)-bond was formed by an intramolecular thermal ene reaction. Further elaboration of 5 involved the ring contraction 6 7, the elimination 8 9 and the final olefin isomerization 9 1.
Application of the Lewis acid mediated [3+2] cycloaddition of allyl- TERT-butyldiphenylsilane combined with a modified Fleming-Tamao oxidation provides a stereoselective route to the triquinane sesquiterpene (±)-β-isocomene.
A totalsynthesis of (±)-isocomene(1) and (±)-β-isocomene (2) employing a chelation-controlled regioselective epoxide–carbonyl rearrangement as the key step has been realized.
A total synthesis of (±)-isocomene and (±) β-isocomene by an intramolecular ene reaction
作者:W. Oppolzer、K. Bättig、T. Hudlicky
DOI:10.1016/0040-4020(81)80001-4
日期:1981.1
sesquiterpenes isocomene 1 and β-isocomene 22 have been synthesized starting from 1,7-octadien-3-one 10 in a stereoselective manner. In the key step 12 → 13 (Scheme 5) the C-7, C-8-bond was formed by an intramolecular thermal enereaction. Further transformations of 13 (Scheme 6) involved successively ring contraction 18 → 19, elimination 21 → 22 and olefin isomerization 22 → 1.