The Preparations of 1, 2-Oxathiin-4 (3 H)-one 2, 2-dioxides

Abstract

The reactions of 1-indanone 1 a or 3, 4-dihydro-1(2 H)-naphthalenone (1 b) in carboxylic acid anhydrides (acetic, propionic and butanoic) in the presence of sulfuric acid afforded the corresponding 3-substituted 5 H-indeno[2, 1-e][1, 2]oxathiin-4(3 H)-one 2, 2-dioxides [3 a, 2 c and 2 d], and 3-substituted-5, 6-dihydronaphtho[2, 1-e][1, 2]oxathiin-4(3 H)-one 2, 2dioxides (3 b, 2 e and 2 f), respectively. On the other hand, the reaction of 1 a or 1 b with acetic anhydride in the presence of sulfoacetic acid gave the corresponding 4-pyranones (4 a or 4 b).