Synthetic methods. 36. Utilization of ethyl 2-((phenylsulfonyl) methyl) acrylate for the synthesis of. alpha.-methylenevalerolactones

E Ghera, T Yechezkel, A Hassner

Index: Ghera, Eugene; Yechezkel, Tamar; Hassner, Alfred Journal of Organic Chemistry, 1990 , vol. 55, # 24 p. 5977 - 5982

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Citation Number: 22

Abstract

A two-step sequence is described for conversion of cyclic and acyclic ketone enolates into a- methylenevalerolactones. The first step involves Michael addition to ethyl a- ((phenylsulfony1) methyl) acrylate 1 with concomitant elimination of PhS02 and formation of unsaturated keto esters 2-7. In the next sequence chemoselective ketone reduction is usually followed by spontaneous lactonization of acidification. Contrary to the five-and six- ...