Diastereoselectivity Chelate Cram model

Organomagnesium addition to alpha-alkoxy ketones

Background Colour:

 


diastereoisomer

Me2Mg chelates if R is small and the major product is produced via addition to the less hindered face of the chelated intermediate. Chelation also increases the rate of addition.

A. Mengel and O. Reiser, Chem. Rev., 1999, 99, 1191–1224.

Link to zinc borohydride chelation-controlled reduction