Water → HCID 57152591, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 3-O-benzyl-N-benzyloxycarbonyl-2,5-dideoxy-2,5-imino-D-lyxose (15) (900 mg, 2.54 mmol), in a 1:1 mixture of water and 1,4-dioxan (15 ml) containing barium carbonate (1.46 g, 7.62 mmol), was cooled to 0° C. and treated with bromine (298 μl, 5.33 mmol). After stirring for 24 hours excess bromine was destroyed by the dropwise addition of 10% sodium thiosulphate solution and the suspension acidified with 2M HCl (20 ml). The product was extracted into dichloromethane (4×50 ml), dried, filtered and evaporated. Purification by flash chromatography (ethyl acetate-hexane (1:1 to ethyl acetate) afforded (2S,3R,4R)-3-benzyl-N-benzyloxycarbonyl-4-hydroxyproline (738 mg, 75%) as a clear oil, [α]20D -3.7° (c, 0.88 in chloroform); νmax (film) 3400 (OH), 2950, 1680 (2×CO), 1425, 1360 and 1195 cm-1 ; 1H NMR δ 3.62-3.78 (2H, 2×dd, H-5); 4.21, 4.26 (2H, s, and bs, H-3, H-2); 4.49-4.69 (3H, m, CH2Ph); 5.06-5.18 (2H, 2×dd, CH2 -Z); 5.6 (2H, bs, 2×OH); 7.27-7.38 (10H, m, 2×H-Ph). m/z: 91 (100%), 310 (45%), 372 (M+H+, 30%).

Provenance & Evidence