Synlett 1999; 1999(5): 529-532
DOI: 10.1055/s-1999-2692
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Preparation of the Synthetic Equivalents of Chiral Cyclohexadienone and Cycloheptadienone: The Enantio- and Diastereo-controlled Synthesis of (-)-Clavularin B

Kou Hiroya* , Huilan Zhang, Kunio Ogasawara
  • *Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan; Fax +81-22-2 17-68 45; E-mail: konol@mail.cc.tohoku.ac.jp
Further Information

Publication History

Publication Date:
31 December 1999 (online)

Both enantiomeric tricyclic enones 2 and 3 serving as the synthetic equivalents of chiral cyclohexadienone and cycloheptadienone have been prepared by lipase-mediated kinetic ester ex-change reaction as the key step. The absolute configuration of the latter has been determined by transformation of the (-)-enantiomer 3 into the known (-)-6-methyl-2-cycloheptenone 16 and the cytotoxic marine natural product (-)-clavularin B 19. However, it has been found that the seven-membered enone 3 exhibits lower diastereoselectivity and less favorable thermal stability than the five-membered and six-membered analogues.

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