SYNTHESIS OF THE 4 STEREOISOMERS OF 4-AMINOADAMANTANE-2-CARBOXYLIC ACID, RIGID ANALOGS OF GAMMA-AMINOBUTYRIC ACID

Synthetic routes to the 4 stereoisomers of 4-aminoadamantane-2-carboxylic acid are described. .pi.-Route cyclizations to 2,4-disubstituted adamantanes are expanded to obtain 4eq- and 4az-acetamidoadamantan-2-ones. These are converted into acetamido-nitriles using tosylmethyl isocyanide and subsequently hydrolyzed to 3 of the amino-acids. The diaxial isomer is prepared by a stereospecific nitrene insertion reaction. Mass spectra of the amino-acids and their ethyl esters are reported. [Biological activity of the compounds is described.].