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Report | Regular issue | Vol 16, No. 9, 1981, pp.1569-1572
Published online, 1st January, 1970
DOI: 10.3987/R-1981-09-1569
Activated Lactams. Ring-expanding Reaction of Ketene-S,N-acetals with Dimethyl Acetylenedicarboxylate

HIroki Takahata, Akira Tominaga, and Takao Yamazaki*

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan


Reaction of ketene-S,N-acetals (1a,b,c) with DMAD gave ring-expanded products (3a,b,c) in good yields. In a similar manner, the reaction of ketene-S,N-acetal derivatives (4a,b,c) also afforded the corresponding ring-enlarged compounds (5a,b,c).