| 摘要 |
1345041 Pregnane polyols; periplogenin FARBWERKE HOECHST AG 18 Jan 1971 [28 Jan 1970] 2248/71 Heading C2U The invention comprises 3#,5,14,21-tetrahydroxy - 5#,14# - pregnan - 20 - one (X) and the 3,21-bis-(2-tetrahydropyranyl) ether thereof (XI), and their preparation from a 20-ketal-21- acyloxypregna - 4,14 - dien - 3 - one (IV) wherein the ketal group is ethylenedioxy or 2,2-dimethyltrimethylenedioxy (vide Specification 1,345,042) by the sequence: IV # 3#- hydroxy - 20 - ketal - 21 - (hydroxy or acyloxy) pregna - 4,14 - diene # 3#,21 - diacyloxy-20- ketalpregna - 4,14 - diene # 3#,21 - diacyloxy- 4#,14# - dihydroxy - 5α,15α- dibromo - 20 - ketalpregnane # 3#,21 - (dihydroxy or diacyloxy)- 4#,5#; 14#,15# - diepoxy - 20 - ketalpregnane # X 20-ketal # X # XI. Periplogenin is prepared from X or XI by reaction with lithium ethoxyacetylide followed by acidification.
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