N, N‐Dialkylamide der 2‐Hydroxy‐2‐phenyl‐cyclopropan‐1‐carbonsäure – photochemische Darstellung und Strukturuntersuchung

N,N‐Dialkylamides of 2‐Hydroxy‐2‐phenyl‐cyclopropan‐1‐carboxylic Acid – Photochemical Synthesis and Determination of the Structure Irradiation of N,N‐dialkylamides of β‐benzoylpropionic acid 2a , b in ether by n,π*‐excitation leads to the corresponding amides of the hitherto unknown 2‐hydroxy‐2‐phenyl‐cyclo‐propancarboxylic acid 3a , b , 4a , b . The photocyclization yields diastereomeric mixtures E:Z = 2.5–3:1. The determination of the relative configurations is based on the different tendency of dimerization of the E and Z diastereomers.