A stereoselective intramolecular 1,3-dipolar nitrone cycloaddition for the synthesis of substituted chromanes.
A stereoselective intramolecular 1,3-dipolar nitrone cycloaddition useful in the synthesis of chromanes is described. The reaction relies on the use of a chiral auxiliary on the nitrone partner. Key to the success of the reaction is the choice of auxiliary and the choice of Lewis acid catalyst. Utilizing an auxiliary with a pendant coordinating group, and Zn(OTf)(2) as the Lewis acid, diastereoselectivities up to 22:1 could be achieved.
Zhao
Qian
Q
Medicinal Chemistry Research, Structural, Analytical, and Medicinal Chemistry, Pharmacia & Upjohn, Pharmacia Corp., Kalamazoo, Michigan 49009, USA.
Han
Fusen
F
Romero
Donna L
DL