A Divergent Synthesis of Functionalized Unsaturated δ-Lactones from α-Alkenoyl-α-carboxyl Ketene Dithioacetals

J Liu, M Wang, B Li, Q Liu, Y Zhao

Index: Liu, Jun; Wang, Mang; Li, Bing; Liu, Qun; Zhao, Yulong Journal of Organic Chemistry, 2007 , vol. 72, # 12 p. 4401 - 4405

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Citation Number: 27

Abstract

A divergent synthesis of functionalized unsaturated δ-lactones 2, 3, 4, and 5 has been developed starting from the readily available α-alkenoyl-α-carboxyl ketene dithioacetals 1 in high to excellent yields under mild reaction conditions. Thus, 6-substituted 3-(1, 3- dithiolan/dithian-2-ylidene)-3 H-pyran-2 (6 H)-ones 2, obtained from a consecutive reduction with NaBH4 and acidic workup of 1 via a novel vinylogous Pummerer cyclization, can be ...