1: (2S)-8-[(1R)-1,3-diphenylpropyl]-5,7,3',4'-tetramethoxyflavan With ruthenium trichloride; sodium periodate in tetrachloromethane; water; acetonitrile T=20°C; Oxidation; 2 h; 2: diphenyldiazo-methane in tetrahydrofuran; methanol T=20°C; Alkylation; 65 h;

1: (2S)-8-[(1R)-1,3-diphenylpropyl]-5,7,3',4'-tetramethoxyflavan With ruthenium trichloride; sodium periodate in tetrachloromethane; water; acetonitrile T=20°C; Oxidation; 2 h; 2: diphenyldiazo-methane in tetrahydrofuran; methanol T=20°C; Alkylation; 65 h;