On the conformations of isomeric trimethyl -methylcyclohexane-1,2,3-tricarboxylates

Balasubrahmanyam, SN and Balasubramanian, Madhusudhanan (1970) On the conformations of isomeric trimethyl -methylcyclohexane-1,2,3-tricarboxylates. In: Journal of the Chemical Society B: Physical Organic . pp. 212-217.

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Abstract

A study has been made of the stereochemistry of three of the four possible configurational isomers of trimethyl 1-methylcyclohexane-1,2,3-tricarboxylate. Two of the isomers undergo highly stereoselective methylation at the 3-position; the third cannot be methylated under similar conditions. Conformations have been suggested for these three isomers on the basis of n.m.r. results. It is thought that axial ester groups at the 1-position in the first two solvate the axial protons at the 3-position and facilitate their removal by trityl anion, while in the third, which has an axial methyl at the 1-position, the effect is not possible and the anion is not formed. The role of A(1.3) strain in causing the high stereoselectivity and position-specificity in the two cases where alkylation does take place and the reasons for slow inversion at the anion centre at position 3 in one of them are discussed.

Item Type:	Journal Article
Publication:	Journal of the Chemical Society B: Physical Organic
Publisher:	Elsevier B.V.
Additional Information:	Copyright of this article belongs to Elsevier B.V.
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	20 May 2010 06:09
Last Modified:	25 Feb 2019 09:24
URI:	http://eprints.iisc.ac.in/id/eprint/27953

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