Cyano ketones ring-expansion

Ring enlargement reactions also take place in 2-oxocycloalkane-l-carbonitri-les substituted in 1-position by an co-alkylester or ketone [17]. The introduction of cyano groups into the a-position of cycloalkanones can be carried out in CH2C12 with C1S02NC0 in dimethylformamide [18]. Two and three carbon atom ring expansion reactions are possible by this method. In most cases the yields are low, which is in contrast with the results of the lactonisation (compare... 

The one-carbon expansion of cyclohexanones with introduction of a carbonyl group, trifluromethyl, cyano, phosphonate or benzenesulfonate has also been reported to proceed in the presence of Lewis acids (Scheme 14). The analogous reactions of larger ring ketones [expressed as ring size (yield)] with ethyl diazoacetate [7 (81%), 8 (85%)] and phenylsulfonyldiazomethane [7 (86%), 8 (27%), 12 (43%), 14 (48%), 15 (54%) and 16 (58%)] have also been reported. In the reaction of ethyl diazoacetate and... 

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