ChemInform Abstract: SYNTHESIS AND IN VITRO ANTIBACTERIAL ACTIVITY OF PENICILLINS CONTAINING THE PHENYLCYCLOHEXANE GROUP

Abstract

Durch Umsetzung von Aminopenicillansäure mit N‐Benzyloxycarbonylaminosäuren in Gegenwart von Dicyclohexylcarbodiimid und folgender Hydrierung wurden die Penicilline (III) rein erhalten.

Synthesis of Enantiomerically Pure 1-Amino-2-phenylcycloalkanecarboxylic Acids (cnPhe)

“…53,58 The stereochemical assignment of the cyclohexane analogues obtained in both reactions is contradictory. Conclusive results seem to indicate that cis-amino acids were obtained under Bucherer-Bergs conditions and trans analogues by means of the Strecker reaction.…”

“…The second strategy to obtain 1-amino-2-phenylcyclohexanecarboxylic acids (approach B, Scheme 20) employs 2-phenylcyclohexanone as the starting material in Bucherer-Bergs and classical Strecker reactions. 53,58 The stereochemical assignment of the cyclohexane analogues 57,59 The first strategy described to obtain these compounds in enantiopure form was developed by our group. 60 Taking into account our previous experience of the Diels-Alder reaction, an asymmetric version of the reaction between 1,3-butadiene and chiral (E)-2-cyanocinnamates was developed (Scheme 21).…”

Synthesis and Preparative Resolution of the trans‐Cyclohexane Analogues of Phenylalanine

“…Later, the Strecker reaction and further hydrolysis of nitrile were applied to the synthesis of c 6 Phe. [20] In this case the authors assumed (but didn't prove) the relative configuration of the amino acid as opposite to that found from the Bücherer synthesis, in a similar manner to that described in the synthesis of related 2-alkyl-1-aminocyclohexanecarboxylic acids. [18] The melting point was the only described physical characteristic of c 6 Phe obtained by both the BüchererϪBergs and Strecker routes.…”

“…Different attempts carried out many years ago to synthesise the racemic target compound by this route were not conclusive with respect to the cis/trans stereochemistry of the amino acid formed, probably due to the precari- ous characterisation techniques employed at that time. [19,20] More recently, synthesis of some enantiomerically pure cisand trans-2-substituted 1-aminocyclohexanecarboxylic acids, constrained analogues of isoleucines [33] and threonines, [34] has been described by means of asymmetric Strecker reactions between 2-substituted cyclohexanones and a chiral amine. To the best of our knowledge, the reaction of 2-phenylcyclohexanone has not been reported.…”

“…[18] The melting point was the only described physical characteristic of c 6 Phe obtained by both the BüchererϪBergs and Strecker routes. [19,20] Different attempts to determine the relative stereochemistry on the basis of NMR studies of several derivatives [21] or precursors [22] led to contradictory assignments, therefore the synthesis of trans-c 6 Phe by Strecker or related reactions remains so far uncertain.…”