A new synthesis of (±) and (+)-2,6,7, 7a-tetrahydro-1β-hydroxy-4-formyl-7aβ-methylindenes

Saibaba, R. ; Banerjee, D. K. ; Kasturi, T. R ; Mukherjee, J. (1987) A new synthesis of (±) and (+)-2,6,7, 7a-tetrahydro-1β-hydroxy-4-formyl-7aβ-methylindenes Proceedings of the Indian Academy of Sciences - Chemical Sciences, 99 (5-6). pp. 327-339. ISSN 0253-4134

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Official URL: http://www.ias.ac.in/j_archive/chemsci/99/3/327-34...

Related URL: http://dx.doi.org/10.1007/BF02880456


A new method for the preparation of the synthon (±)-2,6,7,7a-tetrahydro-1β-hydroxy-4-formyl-7aβ-methylindene (1,a) for the total synthesis of steroids in both (±) and (+) forms, starting from the known β-ketoester, (±)-methyl 1β-t-butoxy-5,6,7,7a-tetrahydro-7aβ-methyl-5-keto-4-indancarboxylate (2,a) has been described. An alternative route to (1,a) has been investigated. Although the compound, (±)-1β-hydroxy-5,6,7,7a-tetrahydro-7aβ-methyl-5-keto-4-methoxymethylindan (2,b) could not be prepared, interesting pathways leading to two unexpected products, (±)-5,6,7,7a-tetrahydro-4,7a-dimethyl-5H-indene-1,5-dione and (±)-2,6-diketo-3-methyltricyclo-(5,2,1,0)decan-8-ol (3 and 4), were encountered during an attempted annelation reaction of the ketone, N-diethylamino-5-methoxypentan-3-one (6), with 2-methylcyclopentan-1,3-dione (5). Trapping of the intermediate, (±)-3a,4,5,6,7,7a-hexahydro-3a-hydroxy-4-methylene-7a-methylindene-1,5-dione (7), through the formation of the adduct, (±)-3a,4,5,6,7,7a-hexahydro-3a-hydroxy-4-(1', 3'-diketo-2'-methylcyclopentano-2'-methylene)-7a-methylindene-1,5-dione (8), established the mechanism of the formation of the products (3 and 4).

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:New Synthesis; Racemic and Asymmetric Synthesis; Steroid Synthone
ID Code:16091
Deposited On:15 Nov 2010 14:14
Last Modified:17 May 2016 00:55

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