反应详情

温度

-60 °C

A solution of oxalyl chloride (105 μl, 1.23 mmol) in CH2Cl2 (2.75 mL) is cooled to -60° C. A solution of DMSO (192 μL) in CH2Cl2 (0.55 mL) is added over a period of 5 min. and the resulting milky mixture is stirred for 15 min at -60° C. The alcohol from Example 39 (133 mg., 0.55 mmol) in CH2Cl2 (0.55 ml) is added to the mixture over 5 min. The bath is allowed to warm up to -20° C. (20 min.) and the clear solution is stirred for 20 min. at -20° C. Triethylamine (0.77 mL) and H2O (3.4 mL) are added and the mixture is stirred for 5 minutes at ambient temperature. Workup with CH2Cl2 gives a crude oil which is purified by chromatography (1.5×20 cm, 3:1 together) to give 9a: NMR δ0.85 (m, 3H), 1.30 (m, 6H), 1.60 (s, 3H), 1.60-1.70 (m, 2H), 1.70 (s, 3H), 2.00-2.40 (m, 2H), 4.00-4.30 (m, 3H), 9.65 (d, J≈1,1H).

1. temperatureto warm up to -20° C. (20 min.)
2. stirringthe clear solution is stirred for 20 min. at -20° C
3. stirringthe mixture is stirred for 5 minutes at ambient temperature
4. customis purified by chromatography (1.5×20 cm, 3:1 together)