Separation of racemic phenyl-?- and?-dialkylamino alcohols into optical isomers

Selective reductions. 37. Asymmetric reduction of prochiral ketones with B-(3-pinanyl)-9-borabicyclo[3.3.1]nonane

“…mp 147-148.5 °C for racemic compound,23 113.5°for R];59 [a]23]} -70.2°(c 0.935, ethanol); 88.9% ee, R; based on [a]235D -78.9°( c 0.935, ethanol)]. 60 The salt was suspended in ether and decomposed by the addition of aqueous potassium carbonate (or sodium hydroxide) until pH 10. The aqueous layer was extracted with ether twice and ether evaporated to obtain the amino alcohol: 100% pure by capillary GC; overall yield 87%.…”

Asymmetric synthesis. Part 6. Asymmetric reduction of aminoketones with (–)-bornan-2-exo-yloxyaluminium dichloride

“…The stereoselectivity, however, considerably decreased (71%) in the reduction of the lower homologue (4). The three acetylpyridines ( 8)-( 10) were reduced to 1-(2-, 3-, and 4-pyridyl)ethanols, but the enantioselectivity was low, the highest being 37% for 3-acetylpyridine (9). They all showed an excess of the dextrorotatory (R)enantiomer l1 in accordance with the transition state ( I 1).…”