I_2-KIO_3-AcOH-H_2O体系氧化3,5-环-24S-乙基-胆甾-22烯-6-酮反应的研究

ON THE OXIDATION OF 3,5-CYCLO-24S-ETHYL-CHOLEST-22-EN-6-ONE BY I_2-KIO_3-AcOH-H_2 O SYSTEM

油莱甾醇内酯(Brassinolide)(1)是一种高效的植物生长激素,其生理活性与侧链中C_(22)、C_(23)的构型密切相关。当C_(22)、C_(23)为S、S构型时,其活性仅为1的十分之一。

The oxidation of 2 by I_2-KIO_3-AcOH-H_2O system has been studied. Instead of 3, thecisglycol(C_(22)S, C_(23)S) was obtained in yield of 78.5%, as the major product obtained in theoxidation of 2 by osmium tetroxide. The possible mechanism,of the oxidation reaction wasdiscussed.