反应详情

(RS)-3-Tetrahydrofuroic acid (3.48 g) in dichloromethane (40 ml) was treated with oxalyl chloride (11.43 g) as described in Example 1 (a). The resultant acid chloride in dichloromethane (40 ml) was then treated with excess diazomethane (60 mM) in ether (100 ml), followed by hydrogen chloride. The solution was washed once with brine, dried and concentrated. Flash chromatography on silica gel, eluting with 40% ethyl acetate/hexane afforded the title compound as a pale yellow oil, (3.924 g, 88%); νmax (CH2Cl2) 1735 and 1716 cm-1 ; 2.17 (2 H, dt, J 7.0, 7.5 Hz), 3.47-3.58 (1 H, m), 3.77-4.04 (4 H, m) and 4.18 (2 H, s); [mass spectrum: +ve ion (ammonia) MNH4+ (166)].

1. washThe solution was washed once with brine
2. customdried
3. concentrationconcentrated
4. washFlash chromatography on silica gel, eluting with 40% ethyl acetate/hexane