115407-84-6Relevant articles and documents
Reagent-Controlled Addition of (R)- and (S)-2-Hydroxy-1,2,2-triphenylethyl Acetate to Chiral Aldehydes
Mahler, Ulrike,Devant, Ralf M.,Braun, Manfred
, p. 2035 - 2044 (2007/10/02)
The enantiomeric enolates (R)- and (S)-2, generated by double deprotonation of (R)- and (S)-2-hydroxy-1,2,2-triphenylethyl acetate (1) ("HYTRA"), are added to chiral aldehydes 4.It turnes out, that in this aldol reaction, the stereochemistry is largely determined by the configuration of the enolate 2 ("reagent control").Depending on the enantiomer of the reagent 1, which is combined with one of the enantiomerically pure aldehydes 4, either anti or syn adducts 11 and 12 are formed predominantly.The basic hydrolysis of the crude adducts 11/12 affords anti and syn carboxylic acids 5 and 6 in the corresponding diastereomeric ratios.By recrystallization of some of the mixtures 11/12, the esters 11c, 11e, and 11g are available in high diastereomeric and enantiomeric purity.Scope and limitations of the method are discussed.