Science in China Series B. Chemistry, Life Sciences & Earth Sciences 1991-06-01

Studies on steroidal plant-growth regulators (XVII)--a new synthesis of homobrassinolide and (22S, 23S)-22, 23-epi-homobrassinolide.

J L Zhu, W S Zhou

Index: Sci. China,. Ser. B, Chem. Life Sci. Earth Sci. 34(6) , 706-11, (1991)

Full Text: HTML

Abstract

Homobrassinolide (2) and (22S, 23S)-22,23-epi-homobrassinolide (4) were synthesized from stigmasterol in seven steps respectively in 4.7% and 24.1% overall yields. The ratio of 2 to 4 is 1:5. The key step is the highly regioselective formation of the B-homo-7-oxa-lactone ring by oxidation of an enol silyl ether with 3-chloro-peroxybenzoic acid.