Ein neuer Zugang zu enantiomerenreinen β‐Lactamen aus α‐Aminosäuren durch präparative Anwendung der Isonitril‐Nitril‐Umlagerung

Abstract

A New Approach to Enantiomerically Pure β‐Lactams from a‐Amino Acids by Applying the Isonitrile‐Nitrile Rearrangement (S)‐Phenylalanine ( 1 ) was converted into (S)‐3‐benzyl‐2‐azetidinone ( 8b ) by a multistep reaction sequence. The key step of this approach is a stereospecific isonitrile‐nitrile rearrangement ( 3 → 4 ) by flash pyrolysis, which may be performed in 20‐g batches of 3 . An improved procedure for the preparation of (S)‐Phenylalaninol ( 2a ) is described.