Influence of the bridgehead substituent on the stereoselective leuckart reaction of 2-norbornanones - Skeletal rearrangement versus structural retention
Ag. Martinez et al., Influence of the bridgehead substituent on the stereoselective leuckart reaction of 2-norbornanones - Skeletal rearrangement versus structural retention, EUR J ORG C, (15), 2001, pp. 2805-2808
The synthesis of chiral amine norbornane derivatives has been achieved by m
eans of the Leuckart reaction of various 2-norbornanones, We propose an ion
ic mechanism for this process in which the formation of a 2-formylamino-2-n
orbornyl cation is the common initial step. The reaction pathway and the is
olated products are strongly dependent on the nature of the bridgehead subs
tituents; hydrogen and alkyl groups yield only enantiopure 2-norbornyl form
amides with structural retention, whereas O-acyl or N-acyl groups favour a
pinacol-type skeleton rearrangement through a cascade of Wagner-Meerwein re
arrangements and intramolecular transamidations.