BIFUNCTIONAL CHIRAL AUXILIARIES-8 - UTILIZATION OF TARTARIC ACID-DERIVED AUXILIARIES IN ALDOL AND ALKYLATION REACTIONS

The boron enolates of three new homochiral C-2 symmetric 1,3-diacylimi dazolidin-2-ones prepared from natural tartaric acid undergo highly di astereoselective aldol and alkylation reactions. Cleavage of these dia stereomerically pure, adducts gives homochiral (IR,2S)-1-phenyl-2-meth ylpropane-1,3-diol and (2R,3R)-3-hydroxy-3-phenyl-2-methylpropanoic ac id and (2S)-3-phenyl-2-methylpropan-1-ol (>92% ee).. One of these auxi liaries, 4,5-dimethylimidazolidin-2-one, has the lowest effective mole cular weight of any previously reported chiral auxiliary.