REDUCTION OF 2-ALKYL-2-CARBOMETHOXY-CYCLOPENTANONE DERIVATIVES WITH SODIUM-BOROHYDRIDE .2. THE ELUCIDATION OF THE DIASTEREOSELECTIVE CONTROL

The synthesis and reduction of four new 2-substituted beta-keto-ester derivatives (6-9), employing inexpensive sodium borohydride, were achi eved to evaluate the diastereoselectivity of the reduction process of 2-allyl-2-carbomethoxy cyclopentanone derivative (1a) in the same cond itions. These results indicating that the diastereoselective control i n this process depend on blockage of the re-face of (1a) by a proposed carbonyl-pi-stacking type interaction.