A new and efficient chemoenzymatic route to both enantiomers of alpha '-acetoxy and alpha '-hydroxy-alpha-methoxy cyclic enones


Demir A. , Caliskan Z. , Aydin A. , Bicer I.

TETRAHEDRON-ASYMMETRY, cilt.17, ss.786-791, 2006 (SCI İndekslerine Giren Dergi)

  • Cilt numarası: 17
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1016/j.tetasy.2006.01.025
  • Dergi Adı: TETRAHEDRON-ASYMMETRY
  • Sayfa Sayısı: ss.786-791

Özet

A chemoenzymatic synthesis of both enantiomers of the pharmacologically interesting alpha'-acetoxy and alpha'-hydroxy-alpha-methoxy cyclic enones starting from alpha-hydroxy cyclic enones is described. Protection of 1,2-diketones, manganese(III) acetate-mediated acetoxylation followed by enzyme-mediated hydrolysis of alpha'-acetoxy enones gives acetoxy enones 3a-d and hydroxy enones 4a-d with high enantiomeric excesses (up to 99%) and good yields. The transesterification of rac-4b in the presence of DMAP afforded (+)-4b and (-)-3b in high enantiomeric excesses (91-94%) and good chemical yields. (c) 2006 Elsevier Ltd All rights reserved.