Photochemistry of .alpha.,.beta.-unsaturated thiones. Cycloaddition to electron-deficient olefins from higher excited states

Rao, Pushkara V and Ramamurthy, V (1988) Photochemistry of .alpha.,.beta.-unsaturated thiones. Cycloaddition to electron-deficient olefins from higher excited states. In: Journal of Organic Chemistry, 53 (2). pp. 332-339.

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Abstract

Electron-deficient olefins add to thioenone 1 upon m* excitation. Cycloaddition occurs to the thiocarbonyl chromophore preferentially from the less-hindered side to yield thietanes. Thietane formation is stereospecific and regioselective. This addition has been inferred to originate from the second excited singlet, S2(?rx*), state. The exciplex intermediacy has been inferred from the dependence of the fluorescence quenching rate constant on the electron-acceptor properties of the olefin. The observed site specificity and regioselectivity are rationalized on the basis of PMO theory. The observed photochemical behavior of thioenone is different from that of enones.

Item Type:	Journal Article
Publication:	Journal of Organic Chemistry
Publisher:	American Chemical Society
Additional Information:	Copyright of this article belongs to American Chemical Society.
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	25 Sep 2010 06:35
Last Modified:	25 Sep 2010 06:35
URI:	http://eprints.iisc.ac.in/id/eprint/32450

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