New journal of chemistry

A study of the ring-opening of lactides and related cyclic esters by Ph 2 SnX 2 and Ph 3 SnX compounds (X= NMe 2, OR)

MH Chisholm, EE Delbridge

Index: Chisholm, Malcolm H.; Delbridge, Ewan E. New Journal of Chemistry, 2003 , vol. 27, # 8 p. 1167 - 1176

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Citation Number: 43

Abstract

Ph3SnX reacts with L-lactide in the order X= NMe2∼ OMe≫ OPri> OBut in the initial ring- opening event. The rate of ring-opening of methyl substituted 1, 4-dioxane-2, 5-diones decreases with methyl substitution and ring-opening of 3, 3, 6, 6-tetramethyl-1, 4-dioxane-2, 5-dione is not observed. From studies of the reaction between Ph3SnOPri and L-lactide the activation parameters ΔH≠= 13 (1) kcal mol− 1 and ΔS≠=− 37 (3) eu have been ...