DIASTEREOSELECTIVE PROCESS FOR PREPARING N-SUBSTITUTED AMINO ACIDS AND DERIVATIVES

摘要

PCT No. PCT/US91/02034 Sec. 371 Date Oct. 6, 1992 Sec. 102(e) Date Oct. 6, 1992 PCT Filed Mar. 29, 1991 PCT Pub. No. WO91/17141 PCT Pub. Date Nov. 14, 1991.A process for preparing an (S,S) or (R,R) diastereoisomer of the formula: (* CHEMICAL STRUCTURE *) (X) or salts, esters or amides thereof, wherein R3 and R4 independently represent hydrogen, alkyl, aryl or aryl substituted with halogen, alkyl, nitro or alkoxy, and n and m independently represent integers from one to six, comprising combining a cyanide compound of the formula: M1C(triple bond)N(III) wherein M1 is hydrogen, trimethylsilyl or a metal, with an optional proton source, a solvent and a Lewis acid of the formula: M2X4, AlCl3 or BF3(IV) wherein M2 is Sn or Ti and X represents chloro, bromo, fluoro or iodo, with an (alpha)-amino acid compound or salts or esters thereof, followed by addition of an acyl or acetal compound to give the diastereoisomer of formula (X).