Chiral Mitsunobu reactions with (1S)-(+)-ketopinic acid: kinetic resolutions of secondary alcohols

Chandrasekhar, Sosale and Kulkarni, Guruprasad (2002) Chiral Mitsunobu reactions with (1S)-(+)-ketopinic acid: kinetic resolutions of secondary alcohols. In: Tetrahedron: Asymmetry, 13 (6). 615-619 .

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Abstract

Several secondary alcohols undergo the Mitsunobu reaction with triphenylphosphine, diethyl azodicarboxylate and (1S)-(+)-ketopinic acid (0.5 equiv. each relative to alcohol) in CH2Cl2 solution at -23degreesC, to furnish the chiral secondary alcohol and its ketopinate ester (d.e. >95%,). Chromatographic separation of these and subsequent hydrolysis of the ketopinate ester (KOH EtOH/0degreesC) provides the chiral secondary alcohol in overall yields of similar to75% and e.e. of similar to80%. When the above Mitsunobu reaction is performed with 1 equiv. of all the reactants. an effective dynamic kinetic resolution of the alcohol is observed in two cases, the ketopinate esters being isolated in 63 and 75% yields and >95% d.e. (C) 2002 Elsevier Science Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	Tetrahedron: Asymmetry
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	22 Jul 2011 09:59
Last Modified:	22 Jul 2011 09:59
URI:	http://eprints.iisc.ac.in/id/eprint/39045

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