Differentiation and assignment of the proton NMR signals in the bis-MTPA ester of meso-alpha,alpha-dimethyl-1,4-benzenedimethanol

NaBH4 reduction of one ketone in 1,4-diacetylbenzene followed by Amano PS catalyzed acylation of the R enantiomer, separation of the R acetate from the S alcohol, and reduction of the remaining ketone in each with NaBD4, has provided two mixtures of monodeuterated diol diastereomers: R,R(d) plus R,S(d) and S,R(d) plus S,S(d). Conversion of the unseparated diols into their bis-(R)-MTPA (Mosher's) esters has allowed the NMR signals arising from the C-methyl groups at the R and the S ends of meso-alpha,alpha-dimethyl-1,4-benzenedimethanol bis-(R)-MTPA ester to be assigned unequivocally. Copyright (C) 1996 Published by Elsevier Science Ltd