1: (4-methoxybenzyl)triphenylphosphonium chloride in tetrahydrofuran; hexane T=-78°C; 1 h; Inert atmosphere; 2: N-(3,4,5-trimethoxybenzylidene)-p-toluenesulfonamide in tetrahydrofuran; hexane T=-78 - 20°C; 12 h; Inert atmosphere; optical yield given as percent destereoselective reaction;