反应详情

Crude intermediate (c) (418 mmol) was dissolved in CH2Cl2 (275 mL) and triethylamine (58.3 mL, 418 mmol) was added followed by ethyl chloroformate (d) (39.8 mL, 418 mmol). The reaction was stirred at ambient temperature for about 24 h. After the reaction was complete, the volatile components were removed under vacuum. The crude product was then distilled under vacuum (about 5 mm Hg) and dissolved in EtOAc which was washed with aqueous saturated KHSO4×3, with brine×1 and dried over Na2SO4. Following filtration, the volatile components were removed under vacuum to afford intermediate (e) as a clear oil (74.8 g, 272 mmol) in 65% yield over two steps.

1. customthe volatile components were removed under vacuum
2. distillationThe crude product was then distilled under vacuum (about 5 mm Hg)
3. dissolutiondissolved in EtOAc which
4. washwas washed with aqueous saturated KHSO4×3, with brine×1
5. dry with materialdried over Na2SO4
6. filtrationfiltration
7. customthe volatile components were removed under vacuum