Water → HCID 46941502, compound

Participants

Reaction Steps

A mixture of diethyl L-tartrate (309 g, 1.5 mol), ethyl vanillin (166 g, 1 mol), toluene (2 L) and p-toluenesulfonic acid (5 g, 0.026 mol) was heated at 115°-116° C. for 24 hours under a nitrogen atmosphere. During the reaction, water was removed by azeotropic distillation via a Dean-Stark trap. The mixture was washed sequentially with saturated sodium bicarbonate solution (500 mL), brine (2×1 L) and dried over sodium sulfate. The solvent was evaporated under reduced pressure and the solid obtained was recrystallized from isopropanol to provide 120 g (34% yield) of (4R,5R)-2-(3-ethoxy-4-hydroxy-phenyl)4,5-dicarboethoxy-1,3-dioxolane, mp 78°-80° C., [α]D25 -38° (c,1.0, methanol). 1H-HMR (CDCl3)δ 7.17 (1H,d,J=1.8 Hz), 7.06 (1H,dd,J=1.8 Hz and 8.10 Hz), 6.91 (1H,d,J= 8.2 Hz), 6.07 (1H,s), 5.83 (1H,s), 4.91, (1H,d,J=4.0 Hz), 4.80 (1H,d,J=4.0 Hz), 4.37-4.25 (4H, 2 q, overlapping, J=7.2 Hz), 4.15 (2H,q,J=7.0 Hz), 1.45 (3H,t,J=7.0 Hz), 1.38-1.29 (6H,2 t, overlapping J=7.2 Hz). IR (KBr) 3390, 2980, 2930, 1735, 1600 cm-1. MS m/e (% abundance) 354 (55), 326 (3), 281 (40), 182 (85), 167 (85), 154 (100), 137 (70), 110 (30), 93 (10), 81 (10), 53 (5).

Provenance & Evidence