1: O,N-dimethyl-hydroxylamine hydrochloride With trimethylaluminum in tetrahydrofuran; hexane T=0 - 20°C; Metallation; 2: (2'R,3'S,4'S,4R,5S)-3-[3'-hydroxy-5'-(4"-methoxyphenyl)methoxy-2',4'-dimethylpentanoyl]-5-phenyl-4-methyl-2-oxazolidinone in tetrahydrofuran; hexane T=-20°C; Substitution; 2.5 h; Further stages.;