抄録
Stereospecific synthesis of isomeric 4-benzoyloxycyclohexane-spiro-5'-hydrantoins from 4-benzoyloxycyclohexanone was achieved via the Bucherer hydantoin synthesis and the Strecker cyanate route. Subsequent hydrolysis of both hydantoins resulted in the formation of 1-amino-trans- and cis-4-hydroxycyclohexane-1-carboxylic acids. The stereochemistry of both amino acids was established unequivocally bythe transforma, -tion of phthalimide of the cis-amino acid to the corresponding lactone. Thus, it is concluded that while the Strecker synthesis leads to the exclusive formation of the cis-amino acid, the Bucherer synthesis gives the trans-amino acid predominantly. The present result provides chemical evidence for the stereochemistry of 1-amino-4-alkylcyclohexane-1-carboxylic acids which have been assigned ambiguously. Physicochemical data of pairs of isomeric 4-substituted amino acids and their derivatives are also summarized.
