Microscale determination of the absolute configuration of alpha-aryl-substituted alcohols by the CD exciton chirality method

The absolute configurations of a broad spectrum of aryl alcohols 1 have bee n determined for the first time by the CD exciton chirality method. The con figurational assignment is additionally verified by computer modeling and l ipase-catalyzed acetylation of the racemic alcohols. The CD-spectroscopic d ata have revealed that the S enantiomers of the benzoate derivatives 2 disp lay a positive first Cotton effect and the R enantiomers a negative one at around 228 nm. Thus, the sense of the first Cotton effect of the benzoate d erivative 2 allows a reliable assignment of the absolute configuration of t he corresponding alcohol 1.