Tetrahedron letters

Gem-disubstituent effects in small ring formation: Novel ketal ring size effect

ME Jung, R Marquez

Index: Jung, Michael E.; Marquez, Rodolfo Tetrahedron Letters, 1997 , vol. 38, # 37 p. 6521 - 6524

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Citation Number: 36

Abstract

While reaction of the bromoalkene with a 5-membered ketal 6a with tributyltin hydride gave only the acyclic product 18a, reaction of the corresponding bromoalkene with a 6-membered ketal 6b gave good yields of the cyclobutane 17b, in a novel ketal ring size effect. Also the gem-dicarboalkoxy effect was operative in these systems, eg, cyclization of the bromo alkene triester 11a afforded reasonable yields of the cyclobutane 19.