Biomimetic asymmetric synthesis. Enantioselective Weitz-Scheffer epoxidation of vitamin K3 and analogs in the presence of cyclodextrins

S Colonna, A Manfredi, R Annunziata…

Index: Colonna; Manfredi; Annuziata; Gaggero; Casella Journal of Organic Chemistry, 1990 , vol. 55, # 23 p. 5862 - 5866

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Citation Number: 45

Abstract

The asymmetric epoxidation of vitamin K3 and analogues in aqueous alkaline buffer solution or in DMF/solid Na2C03, in the presence of a-and 8-cyclodextrin has been investigated. The enantiomeric excesses in the products were up to 48%. The various factors that control the enantioselectivity of the process have been examined. Different mechanisms are involved in aqueous medium and dipolar aprotic solvent.