(R)-2-Phenylglycine ethyl ester was found to be a cheap and effective auxiliary for the preparation of aliphatic α,α-difluoro- β 3-amino esters via a Reformatsky reaction performed under sonication conditions. The products were obtained in good to high yield and ≥96:4 dr, thus providing a new stereoselective route to this under-represented class of compounds. A facile one-pot removal of the phenylglycine moiety and concomitant Boc protection subsequently afforded the corresponding Boc-protected β 3-amino esters in excellent yield.
|Number of pages||4|
|Publication status||Published - 6 Jan 2012|