1: (R,R)-2,6-bis(2-isopropylphenyl)-3,5-dimethylphenyl 3-(2-methoxyphenyl)amino-3-phenylpropionate With tetra(n-butyl)ammonium hydroxide in tetrahydrofuran T=0°C; Saponification; 2: TMSCH2N2 in methanol T=20°C; Methylation; 3: With (NH4)2S2O8; silver nitrate in tetrahydrofuran; water; acetonitrile T=60°C; Oxidative cleavage; Further stages. Title compound not separated from byproducts.;