A solution of the product of Example 25 (122 mg), acetone (23 mg), and acetic acid (19 mg) in dichloroethane (3 mL) was treated with sodium triacetoxyborohydride (96 mg). After 14 h, the reaction was quenched with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (120 mL). The organic phase was dried (magnesium sulfate) and evaporated in vacuo. Silica gel chromatography of the residue (5% 2M ammonia-methanol/dichloromethane) gave the title compound as a white solid (31 mg). 1H NMR (400 MHz, CDCl3): 6.91-6.87 (m, 2H), 6.85-6.81 (m, 2H), 3.95 (t, J=6.4 Hz, 2H), 3.10 (t, J=4.9 Hz, 4H), 2.69 (t, J=4.9 Hz, 4H), 2.48-2.44 (m, 2H), 2.39 (bs, 4H), 1.98-1.91 (m, 2H), 1.61-1.56 (m, 4H), 1.46-1.40 (m, 2H), 1.09 (d, J=6.5 Hz, 6H).
