Double and triple asymmetric induction in phosphaaldol reactions

A multiple asymmetric induction synthesis was applied to increase the stereoselectivity of the phosphaaldol reaction. The double stereoselectivity was achieved in the reaction of chiral di(1R,2S,5R)-menthyl phosphite 3 with chiral 2,3-D-isopropyliden-(R)-aldehyde 2. The reaction of aldehyde 2 with phosphite 1 in the presence of chiral (R)-ALB catalyst proceeding under stereochemical control of three chiral auxiliaries was the most stereoselective to support the conception of multiplicativity of facial selectivities of chiral reactants involved into the reaction. The stereochemistry of the phosphaaldol reaction was in agreement with Cram's rule. The absolute configuration of the new chiral compounds was established on the basis of NMR and X-ray analysis. (C) 2004 Elsevier Ltd. All rights reserved.