Highly Enantioselective Claisen Rearrangement of Imidates Derived from Primary Allyl Alcohols.
A highly enantioselective and diastereoselective Claisen rearrangement of N-arylimidates derived from an axially chiral binaphthylamine auxiliary is reported. Upon deprotonation of the imidates with lithium diethylamide, the resultant azaenolates rearrange at 0 degrees C to give anti alpha,beta-disubstituted, gamma,delta-unsaturated N-binaphthyl amides. A iodolactonization/zinc reduction sequence readily converts these amides into the corresponding carboxylic acids of 91-95% ee and allows an efficient recovery of the chiral auxiliary.
Metz
Peter
P
Institut für Organische Chemie, Technische Universität Dresden, Mommsenstrasse 13, D-01062 Dresden, Germany.
Hungerhoff
Benno
B