反应详情

A solution of the ester 3 (19.5 g, 85 mmol) in THF (326 mL) was cooled to 0□C (ice/acetone) and treated with LiBH4 (2.78 g, 128 mmol) in portions. The reaction mixture was allowed to warm to room temperature and stirred under a nitrogen atmosphere for 2.5 hours at which time TLC (50% EtOAc/Petroleum Ether) revealed complete consumption of ester 3. The mixture was cooled to 0° C. and water (108 mL) was carefully added followed by 2 N HCl (54 mL). After evaporation of the THF in vacuo, the mixture was neutralised to pH 7 with 10 N NaOH and saturated with solid NaCl. The saturated aqueous solution was then extracted with EtOAc (5×100 mL), the combined organic layers washed with brine (200 mL), dried (MgSO4), filtered and evaporated in vacuo to furnish the pure diol 4 as a clear colourless oil (16.97 g, 99%): [α]24D=−57.0° (c=0.61, CHCl3); 1H NMR (270 MHz, CDCl3) δ 6.01-5.87 (m, 1H, NCO2CH2CH═CH2), 5.36-5.20 (m, 2H, NCO2CH2CH═CH2), 4.84 (br s, 1H, NCHCH2OH), 4.60 (d, 2H, J=5.31 Hz, NCO2CH2CH═CH2), 4.39 (br s, 1H, NCHCH2OH), 4.18-4.08 (m, 1H, 3.35, NCH2CHOH), 3.90-3.35 (m, 4H, NCH2CHOH, NCHCH2OH, and OH), 3.04 (brs, 1H, OH), 2.11-2.03 (m, 1H, NCH2CHOHCH2), 1.78-1.69 (m, 1H, NCH2CHOHCH2); 13C NMR (67.8 MHz, CDCl3) δ 157.1 (NC═O), 132.6 (NCO2CH2CH═CH2), 117.7 (NCO2CH2CH═CH2), 69.2 (NCH2CHOH), 66.4 and 66.2 (NCO2CH2CH═CH2 and NCHCH2OH), 59.2 (NCHCH2OH), 55.5 (NCH2CHOH), 37.3 (NCH2CHOHCH2); MS (EI), m/z (relative intensity) 201 (M+, 2), 170 (M-CH2OH, 100), 144 (M-OC3H5, 6), 126 (26), 108 (20), 68 (9); IR (Neat) 3394 (br, OH), 2946, 2870, 1679 (C═O), 1413, 1339, 1194, 1126, 1054, 980, 772 cm−1; exact mass calcd for C9H15NO4 m/e 201.1001, obsd m/e 201.1028

1. customconsumption of ester 3
2. temperatureThe mixture was cooled to 0° C.
3. additionwater (108 mL) was carefully added
4. customAfter evaporation of the THF in vacuo
5. extractionThe saturated aqueous solution was then extracted with EtOAc (5×100 mL)
6. washthe combined organic layers washed with brine (200 mL)
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. customevaporated in vacuo