反应详情

Compound 103c was prepared, likewise the procedure described for 103b, starting from butyl cyclopentanecarboxylate (Payne, G. B. et al. J. Org. Chem., 1957, 22, 1680-1682) (80.0 g, 0.42 mol), 1,4-dibromobutane (183.3 g, 0.84 mol) and LDA (2 M in THF/heptane/ethylbenzene, 250 mL, 0.50 mol) to give, after purification by fractional distillation under reduced pressure, 103c (62.8 g, 49%) as a light yellow liquid. bp: T=116-117° C. (p=0.040-0.051 Torr). 1H NMR: δ 4.07 (t, J=6.6 Hz, 2H), 3.38 (t, J=6.8 Hz, 2H), 2.16-2.10 (m, 2H), 1.83 (quintet, J=7.1 Hz, 2H), 1.65-1.59 (m, 8H), 1.50-1.31 (m, 6H), 0.94 (t, J=7.2 Hz, 3H). 13C NMR: δ 177.6, 64.1, 53.9, 38.2, 36.0 (2×), 33.3, 33.0, 30.6, 24.8 (2×), 24.6, 19.1, 13.6. HRMS calcd for C14H25BrO2 (M+): 304.1038, found: 304.1042.

1. customto give
2. customafter purification
3. distillationby fractional distillation under reduced pressure, 103c (62.8 g, 49%) as a light yellow liquid
4. customT=116-117° C. (p=0.040-0.051 Torr)