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PartiaI Syntheses of 21,27 -Bisnordemissidine from Epiandrosterone and Dehydroepiandrosterone Acetates. Crystal and Molecular Structure of 21,27 -Bisnordemissidine Hydrobromide

Dušan Miljković ; Institute of Chemistry, Faculty of Sciences, 21000 - Novi Sad, Veljka Vlahovića 2, Yugoslavia
Katarina Gaši ; Institute of Chemistry, Faculty of Sciences, 21000 - Novi Sad, Veljka Vlahovića 2, Yugoslavia
Marija Kindjer ; Institute of Chemistry, Faculty of Sciences, 21000 - Novi Sad, Veljka Vlahovića 2, Yugoslavia
Slobodanka Stanković ; Institute of Physics, Faculty of Sciences, 21000 - Novi Sad, Ilije Djuričića 4, Yugoslavia
Bela Ribar ; Institute of Physics, Faculty of Sciences, 21000 - Novi Sad, Ilije Djuričića 4, Yugoslavia
Gyula Argay ; Central Research Institute of Chemistry, Hungarian Academy of Sciences, Budapest 114, P.O. Box 17, H-1525 Hungary

Sažetak

Stereoselective syntheses of 21,27-bisnordemissidine from epiandrosterone acetate (1) and dehydroepiandrosterone acetate (la)
are described in this work. These syntheses involve in sequence:
a) stereospecific addition of «-picolyl-Iithium to the C-17 carbonyl
group of 1 (la); b) regio- and chemoselective 17,20-dehydration
of the formed diol 2 (2a) leading to 3~-acetoxy-17-picolinylidene-
-5a-androstane (3) or the corresponding derivative 3a; c) regiospecific allylic oxidation of C-16 in 3 (3a) by Se02 to 4 and chromic acid oxidation to the crucial intermediates (5a-5d); d) stereospecific intramolecular reductive cyclization reaction of 5a-5d,
under carefully chosen reaction conditions, leading to 3~-acetoxy-
-21,27-bisnor-5a-solanidane (6); e) hydrolysis of 6 with conc. aq.
HBr to the target molecule of 21,27-bisnordemissidine hydrobromide
(7); and f) alkaline treatment of 6 and 7 with KOH in MeOH affording 21,27-bisnordemissidine (11). The structure of 7 has been unambiguously proved by the appropriate X-ray structural analysis. Detection and isolation of some intermediates and by-products (8, 9 and 10) during catalytic hydrogenation of 5c and 5d pointed to a possible mechanism of the last and crucial step of the synthesis of 21,27-bisnordemissidine.

Ključne riječi

Hrčak ID:

178058

URI

https://hrcak.srce.hr/178058

Datum izdavanja:

6.3.1986.

Posjeta: 912 *