反应详情

An ice bath cooled methylene chloride (80.0 mL) solution of cis-3-hydroxy-cyclobutanecarboxylic acid methyl ester (4.00 g, 31.0 mmol; predominantly cis) was charged with pyridine (3.00 mL, 37.0 mmol) and Ts2O (11.1 g, 34.0 mmol). After 45 min, TLC analysis (EtOAc) revealed no starting material (KMnO4 stain for alcohol sm). The reaction mixture was concentrated in vacuo, resuspended in ether (50.0 mL) and washed with 0.5 N HCl (2×25 mL), saturated bicarbonate (2×25 mL), water (2×25 mL), brine (1×25 mL), and then dried over Na2SO4, filtered and concentrated to yield the title compound as colorless oil, predominantly cis. 1H NMR (400 MHz, CDCl3): δ=2.44-2.55 (m, 7H), 2.56-2.65 (m, 1H), 3.65 (s, 3H), 4.59-4.77 (m, 1H), 7.33 (d, 2H, J=8.0 Hz), 7.77 (d, 2H, J=8.0 Hz).

1. concentrationThe reaction mixture was concentrated in vacuo
2. washwashed with 0.5 N HCl (2×25 mL), saturated bicarbonate (2×25 mL), water (2×25 mL), brine (1×25 mL)
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated