Acetophenone → 1-Phenylethanol

Participants

Reaction Steps

NaAlH[(S)-BINOL](OMe) gave surprisingly and unexpectedly high conversion (chemical yield) and enantioselectivity values relative to LiAlH[(S)-BINOL](OMe), when admixed with acetophenone (AP). In a comparative experiment, NaAlH[(S)-BINOL](OMe) was admixed with AP in THF at -70° C. to afford 79% 1-phenylethanol (PET) with the (S)-enantiomer in 97% enantiomeric excess, whereas under similar conditions, LiAlH((R)-BINOL)(OMe) afforded only 60% PET with the (R)-enantiomer in only 87% enantiomeric excess (J. Am. Chem. Soc., 1984, 106, 6709). Thus, NaAlH[(S)-BINOL](OMe) is surprisingly and unexpectedly a more efficient and enantioselective reducing agent than its lithium analog.

Provenance & Evidence