BORANES IN SYNTHESIS - VII - SYNTHESIS OF IALKYLAMINO-6,6-DIMETHYLBICYCLO[3.1.1]HEPTAN-3-OLS FROM (R)-(-NOPINONE - CHIRAL AUXILIARIES FOR THE ADDITION OF DIETHYLZINC TO AROMATIC-ALDEHYDES())

The reaction of (1R,SS)-(+)-nopinone with secondary amines in cyclohex ane with the azeoptropic removal of water afforded excellent yields of the corresponding enamines. Hydroboration of these enamines with EMS followed by methanolysis and oxidation with basic hydrogen peroxide ga ve the corresponding alkylamino-6,6-dimethylbicyclo[3.1.1]heptan-3-ols . These amino alcohols, in spite of their trans geometry, served as ch iral auxiliaries for the addition of diethylzinc to aromatic aldehydes to give nearly quantitative yields of the corresponding (R)-1-aryl-1- propanols with 52 to 80% ee. (C) 1997 Published by Elsevier Science Lt d. All rights reserved.