The tetrahedral intermediate of a lactonization reaction

RA McClelland, M Alibhai

Index: McClelland, Robert A.; Alibhai, Masuma Canadian Journal of Chemistry, 1981 , vol. 59, p. 1169 - 1176

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Citation Number: 21

Abstract

The hydrolysis of the ortho ester 1, 1-diethoxy-1, 3-dihydroisobenzofuran (1) is described. This hydrolysis proceeds with initial expulsion of an exocyclic ethoxy group, producing upon hydration of the oxocarbonium ion 1-hydroxy-1-ethoxy-1, 3-dihydroisobenzofuran (7), the tetrahedral intermediate of the lactonization of ethyl (2-hydroxymethyl) benzoate (6) to phthalide (8). Based on the kinetic behavior of the ortho ester hydrolysis, the pH variation ...