摘要：Configurational assignment has been made for three isomeric compounds obtained by the performic acid-oxidation of the enol acetate (II). The major product, which became an important intermediate for the total synthesis of santonin, has been given the structure of ethyl 11-ethoxycarbonyl-6α-hydroxy-3-oxo-11-epi-eusanton-4-enic acid lactone (III), and the other two were proved to be the C11-and the C6-epimer of (III). The mechanism of the oxidation reaction is also discussed briefly.
