反应详情

To a stirred solution of alcohol (5) (400 mg, 3.07 mmol), triphenylphosphine (1.6 g, 61.4 mmol), and p-nitrobenzoic acid (770 mg, 4.61 mmol) in dry benzene (30 mL) at 23° C. was added diisoproylazodicarboxylate (DIAD, 1.2 mL, 6.14 mmol) dropwise. After 1.5 hours, the mixture was concentrated in vacuo, and the crude ester was dissolved in a (4:3:1) mixture of MeOH:Et3N:H2O (24 mL), then treated with LiOH (450 mg, 10.7 mmol). The solution was stirred at room temperature for 2 h. The mixture then was concentrated under reduced pressure and the residue was chromatographed over silica gel to provide the bis-THF (I) (326 mg, 82%); [α]25D −12.4 (c 1.16, MeOH).

1. concentrationthe mixture was concentrated in vacuo
2. dissolutionthe crude ester was dissolved in a (4:3:1) mixture of MeOH
3. concentrationThe mixture then was concentrated under reduced pressure
4. customthe residue was chromatographed over silica gel