Oxidation of spiroketones with DDQ - synthesis of tropone derivatives and DDHQ diesters

Kasturi, Tirumalai R and Pragnacharyulu, Palle VP and Reddy, Gouravaram M and Jayaram, Srirangam K and Singh, Sheo B (1992) Oxidation of spiroketones with DDQ - synthesis of tropone derivatives and DDHQ diesters. In: Tetrahedron, 48 (26). pp. 5481-5496.

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Abstract

Oxidation of spiroketones 3a–f with DDQ in dry benzene gave tropone derivatives 4a–f and DDHQ esters 5a–f (cis -cis isomer 6a–f, (cis -cis isomer 7a–f). While the aryl substituted spirokeone 17a gave a 2:1 mixture of 19a and the corresponding trans -trans isomer, the aryl substituted spiroketones 17b–d gave exclusively trans-trans isomers 19b–d. Heating acid chloride of acid 9c with DDHQ resulted in compounds 4a and 7a, thus confirming the structures assigned. Mechanism of formation of these compounds has been rationalised. A detailed study of 2D 1H-1H COSY, 1H-13C COSY, HMBC and 2D NOESY of compound 7d led to complete assignment of 1H and 13C NMR signals and its solution conformation.

Item Type:	Journal Article
Publication:	Tetrahedron
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	16 Dec 2009 10:02
Last Modified:	19 Sep 2010 05:51
URI:	http://eprints.iisc.ac.in/id/eprint/24619

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