The intramolecular reaction between a diazoalkane group and an ester group: a search for other examples

Abstract

The reactions of eight N-nitroso-lactams with sodium methoxide are described. In most cases the intermediate diazoalkane ester does not give an insertion product of the kind described in the preceding paper, but gives instead the solvolysis products—ethers and/or olefins. The intramolecular reaction between a diazoalkane and an ester group is not therefore a promising one for synthesis. One other example of the diazoalkane ester reaction was, however, observed: 4-nitroso-4-azahomoadamantan-5-one (24) gave a 14% yield of methyl noradamantane-3-carboxylate (27). One other nitroso-lactam, 3-nitroso-3-aza-A-homocholest-4a-en-4-one (32), failed even to give a diazoalkane, but instead rearranged to an isomer, methyl (3-nitroso-3-aza-A-nor-5ξ-cholestan-5-yl)acetate (34).

The partitioning of the intermediate diazotic acids between diazoalkane and solvolysis products indicates that substantial yields of diazoalkanes were realised in most cases. The synthesis of the N-nitroso-lactams is described.