Highly diastereoselective synthesis of new, carbostyril-based type of conformationally-constrained β-phenylserines

We have demonstrated that the readily available amido–keto compounds , with prearranged carbonyl and glycine moieties, under strongly basic conditions easily undergo complete and highly diastereoselective cyclization, affording a generalized and practical access to the conformationally constrained phenylserine derivatives . High chemical yields, virtually complete diastereoselectivity combined with the operational convenience of the experimental procedures render this method useful for preparation of these diastereomerically pure derivatives.