1: 4-(hydroxymethyl)phenyl 4-methylbenzene-1-sulfonate; tripropylphosphine hydrohalide in acetonitrile T=100°C; 8 h; 2: 3,5-dimethoxy-benzaldehyde With lithium hydroxide hydrate in water T=90°C; Wittig Olefination; 12 h; stereoselective reaction;