process for the production of 3beta, 5beta, 14beta - trihydroxy - 20 (22), cardenolid (periplogenin)

摘要

The invention comprises (1) 20-a -ethoxyethynyl - 3b ,5b ,14b ,20b ,21 - pentahydroxy-pregnane and its 3,21-diacetate, and (11) a process for preparing periplogenin from the diacetate of the invention by (a) hydrolysis to the pentaol of the invention or 3b ,5b ,14b -20-tetrahydroxy - 20(22) - dihydro - cardenolide, or a mixture of the two, followed by treatment with a dilute mineral acid, or (b) reacting the with a dilute mineral acid, or (b) reacting the diacetate of the invention with a dilute mineral acid to give 20-carbethoxymethylene-3b ,21-diacetoxy - 5b ,14b - dihydroxy - pregnane, followed by hydrolysis and cyclization. 3b ,21 - diacetoxy - 20 - a - ethoxyethynyl-5b ,14b ,20b -trihydroxy - pregnane is prepared by conversion of 14a -desoxycorticosterone to its 21-acetate, dehydration of this to 14-dehydro-desoxycorticosterone acetate, reducing this with lithium aluminium hydride to 3b ,20b ,21-trihydroxy - 4,14 - pregnadiene, converting this to its 3,20,21-triacetate, treatment with N-bromo-acetamide and perchloric acid to form 4a ,14a - dibromo - 3b ,5b ,15b ,20b ,21 - penta-hydroxy - pregnane - 3,20,21 - triacetate, treatment of this with a base to form 4b ,5b ,14b ,15b -diepoxy - 3b ,20b ,21 - trihydroxy - pregnane, converting this to its 20,21-acetonide, reaction of this with lithium aluminium hydride to form 3b ,5b ,14b - trihydroxy - 20b ,21 - isopropylidene -dioxy-pregnane, converting this to its 3-acetate, hydrolysing the acetonide group to form 3b -acetoxy - 5b ,14b ,20b ,21 - tetrahydroxy - pregnane, converting this to its 3,21-diacetate, oxidation to the 20-ketone and reaction with lithium ethoxyacetylene.