Borane;tetrahydrofuran → 4-(1-(3-(Tetrahydro-2H-pyran-2-yloxy)phenyl)-2-oxabicyclo[2.2.2]octan-4-yl)butan-1-ol

To a solution of 4-(1-(3-(tetrahydro-2H-pyran-2-yloxy)phenyl)-2-oxabicyclo[2.2.2]octan-4-yl)butanoic acid (115 mg, 0.307 mmol) in dry THF (1 mL) at 0° C. under N2 was added BH3.THF (0.461 ml, 0.461 mmol) over a period of 3 min. The resulting mixture was stirred at 0° C. for 30 min and at room temperature 3 h. The reaction was cooled to 0° C. and quenched with water carefully. The mixture was extracted with ethyl acetate. The organic layer was washed with sat′d aqueous NaHCO3, water, dried, and the concentrated in vacuo to afford the title compound (111 mg, 100% yield) as a clear oil. 1H NMR (500 MHz, CDCl3) δ 7.23 (t, J=8.0 Hz, 1H), 7.14-7.11 (m, 1H), 7.04-7.00 (m, 1H), 6.94 (ddd, J=8.2, 2.5, 0.8 Hz, 1H), 5.45 (t, J=3.2 Hz, 1H), 3.98-3.91 (m, 1H), 3.83 (s, 2H), 3.67 (t, J=6.5 Hz, 2H), 3.64-3.58 (m, 1H), 2.04 (t, J=7.8 Hz, 5H), 1.90-1.83 (m, 2H), 1.75-1.50 (m, 10H), 1.38-1.26 (m, 2H), 1.22-1.15 (m, 2H).