9α-hydroxylation of 25-fluoroponasterone a diacetonide in lithium-ammonia solution
摘要:
25-Fluoroponasterone A diacetonide reacted with lithium in liquid ammonia to give 25-fluoro-9 alpha,20-dihydroxyecdysone diacetonide whose hydrolysis afforded 25-fluoro-9 alpha,20-dihydroxyecdysone 20,22-acetonide. Nonfluorinated analog of the latter was isolated previously from Silene italica ssp. nemoralis.