Absolute configuration of (–)-2-chloro- and (–)-2-bromo-3,3-dimethylbutanoic acids

Abstract

The absolute configuration of (–)-2-chloro-3,3-dimethylbutanoic acid has been assigned as R on the basis of chemical correlation, g.l.c. separation of diastereomers, c.d. measurements, and Fredenberg's rules. Application of the same methods allows assignment of the R-configuration to (–)-2-bromo-3,3-dimethylbutanioc acid; this is a reveral of an eralier assignment which was based on the incorrect configuration of (+)-α-t-butylglycine.