Selective synthesis of natural and unnatural 5, 6-disubstituted 2 (2H)-pyranones via iodolactonization of 5-substituted (Z)-2-en-4-ynoic acids

F Bellina, M Biagetti, A Carpita, R Rossi

Index: Bellina; Biagetti; Carpita; Rossi Tetrahedron, 2001 , vol. 57, # 14 p. 2857 - 2870

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Citation Number: 86

Abstract

Reaction of 5-substituted (Z)-2-en-4-ynoic acids with iodine and NaHCO3 in CH3CN or with ICl in CH2Cl2 affords mixtures of (E)-5-(1-iodoylidene)-2 (5H)-furanones and 6-substituted 5- iodo-2 (2H)-pyranones in which these last compounds are the major products. The 5-iodo-2 (2H)-pyranones, which are easily separated chromatographically from the corresponding regioisomers, are able to undergo Stille-type reactions with a variety of organotin ...