Photochemistry of stilbenes. VI. Steric effects on the photocyclizations of some m-substituted stilbenes

FB Mallory, CW Mallory

Index: Mallory,F.B.; Mallory,C.W. Journal of the American Chemical Society, 1972 , vol. 94, # 17 p. 6041 - 6048

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Citation Number: 40

Abstract

Abstract: The isomer ratios of the 2-and 4-substituted phenanthrenes produced by the photocyclization in the presence of iodine of a series of meta-substituted stilbenes were determined to assess the importance of steric effects on these photoreactions. The irradiations of m-methyl-, m-chloro-, and m-trifluoromethylstilbene each gave product ratios near unity. From these results and other arguments it is concluded that the more crowded ...