Tetrahedron

Ketene-S, S,-acetals—VI: Synthesis of 3, 3-bis-(methylthio)-2-propene-2-alkyl-1-aryl-1-ones and their reaction with guanidine: A novel route for pyrimidine synthesis

SMS Chauhan, H Junjappa

Index: Chauhan,S.M.S.; Junjappa,H. Tetrahedron, 1976 , vol. 32, p. 1911 - 1916

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Citation Number: 37

Abstract

The α-ketoketene-S, S,-acetals 2a–h have been synthesized from the appropriate ketones 1a–f in good yields by extending the established method. The acetals 2a–d react with guanidine in the presence of sodium ethoxide to give pyrimidines 4a–d in 35–59% overall yields (Scheme 1). Treatment of 2e with guanidine similarly gave 5a in 23% yield. However, the reaction of 2e with guanidine in the presence of sodium n-propoxide gave a mixture of ...