Total synthesis of substituted (±)-6,6-dimethyl-B-norestra-1,3,5(10)-trien-17?-ols and their 9?-isomers

Kasturi, Tirumalai R and Parvathi, Shankaranarayana (1980) Total synthesis of substituted (±)-6,6-dimethyl-B-norestra-1,3,5(10)-trien-17?-ols and their 9?-isomers. In: Perkin Transactions 1 (2). 448-456 .

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Abstract

Total syntheses of (±)-1,4-dimethoxy-6,6-dimethyl-B-norestra-1,3,5(10)-trien-17?-ol(11a), (±)-2,3-dimethoxy-6,6-dimethyl-B-norestra-1,3,5(10)-trien-17?-ol (11b), and (±)-3-methoxy-6,6-dimethyl-B-norestra-1,3,5(10)trien-17?-ol (11c), have been carried out starting from 4,7-dimethoxy-3,3-dimethylindan-1-one (1), 5,6-dimethoxy-3,3-dimethylindan-1-one (2), and 4?-methoxy-3-methylbut-2-enophenone (4), respectively. Generally, it is found that the intermediate 6,6-dimethyl-B-norestra-1,3,5(10),8-tetraen-17?-ols (10), on lithium�liquid ammonia reduction, yield a mixture of 8?,9?- and 8?,9?-trienols, (11) and (12) respectively, in the ratio 1 : 1. This is due to the comparable stabilities of these two isomers. However, the reduction carried out in presence of aniline affords a higher percentage of the 8?,9?-trienol (11). The assignment of configurations is made by chemical and 1H n.m.r. analysis. Catalytic hydrogenation of the tetraenols (10) is shown to proceed via initial isomerisation to the corresponding 6,6-dimethyl-B-norestra-1,3,5(10),9(11)-tetraen-17?-ols (26), followed by hydrogenation from the ?-side to give, exclusively, the 8?,9?-trienols (12).

Item Type:	Journal Article
Publication:	Perkin Transactions 1
Publisher:	Royal Society of Chemistry
Additional Information:	Copyright of this article belongs to Royal Society of Chemistry.
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	10 Jan 2011 12:31
Last Modified:	10 Jan 2011 12:31
URI:	http://eprints.iisc.ac.in/id/eprint/34660

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