反应详情

In a manner similar to Scheme I, 34 (0.19 g) was treated with 2N NaOH in methanol at 0°-5° C. for 18 h, followed by ethyl chloroformate (0.254 mmol) and Et3N in CH2Cl2 at 0°-5° C. Workup and purification of the residue by SiO2 using 1% Et3N in EtOAc as eluent yielded the product. mp 120°-3° C. Anal. C26H34FNO3 ·0.5 H2O: Theory C: 71,53; H: 8.08; N: 3.21; Found C: 71.60; H: 8.17; N: 3.03.

1. customWorkup and purification of the residue by SiO2 using 1% Et3N in EtOAc as eluent
2. customyielded the product