抗哮喘剂IPL576,092的改进合成

Improved synthesis of IPL576,092:a novel anti-asthma agent

摘要: 由去氢表雄酮(DHEA)出发,采用包括NHPI(N-hydroxyphthalimide)/空气/Bz2O2-CuCl2体系进行选择性烯丙位氧化及用BF3·OEt2/NaBH4-NaBO3体系直接对3β-羟基-7-酮-Δ5-甾体进行还原、5硼氢化2个关键步骤,不用保护3-位羟基,共6步合成了IPL576,092,总收率达27%,操作比较简便.

Abstract: An improved synthesis of IPL576,092 has been accomplished starting from the commercially availabbe DHEA(dehydroisoandrosterone) in six steps in 27% overall yields.The procedure involves the selective allyic oxidation of 5-androsten-3β-ol-17-one ethylene ketal by NHPI/O2/Bz2O2-CuCl2 system and the hydroboration of 5-androsten-7,17-dione-3β-ol 17-ethylene ketal by BF3·OEt2/NaBH4-NaBO3 system as key steps.Workup procedures were simplified.