On the basis of the Felkin-Anh model, trends of selectivities obtained in a large number of nucleo-philic additions to R-chiral aldehydes can be convincingly explained (Table 1).14-16 An increase in the steric bulk of the nucleophile renders its addition
more selective toward the Felkin product, as depicted in the reaction of 13 with various Grignard reagents (Scheme 6), since the nucleophile is “more aware” of