Spiroannelation reactions of 3-trifluoroacetyl- and other 3-acyl-1-methyl-lactams
摘要:
3-Trifluoroacetyl- and other 3-acyl-1-methyl-lactams (1-5) undergo the Robinson annelation with alpha,beta-unsaturated ketones to produce spirocyclic cyclohexenones (6), their precursors hydroxycyclohexanones (7) or 3-acyl-3-oxobutyl-lactams (8) depending on the substitution.
Synthesis of 3-(2,2,2-trifluoroethylidene)-lactams. First examples of 1,3-dipolar cycloaddition with diazomethane and N-methyl-α-phenylnitrone
作者:Jean-Philippe Bouillon、Zdenek Janousek、Heinz G. Viehe、Bernard Tinant、Jean-Paul Declercq
DOI:10.1039/p19960001853
日期:——
The preparation of 3-(2,2,2-trifluoroethylidene)-lactams 7–9 is accomplished by reduction of 3-trifluoroacetyl-substituted lactams 1–3 and subsequent dehydration of trifluoromethylated methanols 4–6. 1,3-Dipolar cycloadditions of compounds 7 with diazomethane and N-methyl-α-phenylnitrone give spirocyclic pyrazoline 11 and isoxazolidine 12. The structure of the latter heterocycle is confirmed by X-ray