The photochemical synthesis of alkyl 2,2-dimethyl-3-(2-methylpropenyl)aziridine-1-carboxylates and 3,3-dimethylaziridine-1,2-dicarboxylates from alkyl azidoformates
The photolysis of alkyl azidoformates in 2,5-dimethylhexa-2,4-diene gave alkyl 2,2-dimethyl-3-(2-methylpropenyl)-aziridine-1-carboxylates (azachrysanthemates). Similarly, photolysis of the same azidoformates in alkyl 3-methylcrotonates gave dialkyl 3,3-dimethylaziridine-1,2-dicarboxylates (azacaronates). The copper-catalysed pyrolysis of ethyl azidoformate in 2,5-dimethylhexa-2,4-diene, however, led to a Δ2-oxazoline. An open-chain unsaturated carbamate was obtained, instead of the expected benzyl ester, on treatment of ethyl 2,2-dimethyl-3-(2-methyl-propenyl)aziridine-1-carboxylate with benzyl alcohol. The novel cyclic amino-acid, 3,3-dimethylaziridine-2-carboxylic acid, was prepared by hydrolysis of dimethyl 3,3-dimethylaziridine-1,2-dicarboxylate.