Studies on steroidal plant-growth regulators (XVII)--a new synthesis of homobrassinolide and (22S, 23S)-22, 23-epi-homobrassinolide.
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.
Zhu
J L
JL
School of Pharmacy, Shanghai Medical University, PRC.
Zhou
W S
WS
D002778:Cholestanones / Q000138:chemical synthesis* / Q000737:chemistry; D010937:Plant Growth Regulators / Q000138:chemical synthesis*; D013265:Stigmasterol
D002778:Cholestanones; D010937:Plant Growth Regulators; C070163:homobrassinolide; D013265:Stigmasterol