Nitrile oxide [3+ 2] cycloaddition: application to the synthesis of 6-substituted 3 (2H)-pyridazinones and 6-substituted 4, 5-Dihydro-4-hydroxy-3 (2H)-pyridazinones

…, B Cacciari, C Caldari, S Manfredini, G Spalluto

Index: Baraldi; Bigoni; Cacciari; Caldari; Manfredini; Spalluto Synthesis, 1994 , # 11 p. 1158 - 1162

Full Text: HTML

Citation Number: 28

Abstract

An eflicient method for the preparation of 6-substituted 3 (2H)-pyridazinones and 6- substituted 4, 5-dihydro-4-hydroxy-3 (2H)-py-ridazinones starting from 3, 5-disubstituted 4, 5- dihydroisoxazoles is described. N—O bond cleavage of the isoxazoline ring promoted by molybdenum hexacarbonyl or by catalytic hydrogenation afiordcd the oz-hydroxy y-keto esters 4a—f which were converted into 6-substituted 4, 5-dihydro-4-hydroxy-3 (2H)- ...