To a suspension of LiAlH4 (4.4 mg, 0.116 mmol) in THF (1 mL) was added a solution of 4-benzyloxy-2-[2-(2-isopropyl-5-methyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,3a-diazabenzo[e]azulen-8-yloxy]-2-methylbutyric acid benzyl ester (36 mg, 0.058 mmol) in THF (2 mL) and stirring at RT was continued for 2.5 h. To the reaction mixture was added EtOAc (0.5 mL) and stirring was continued for 10 min. An aqueous solution of Rochelle's salt was then added and the aqueous phase was extracted with EtOAc (×2). The combined organic phases were washed with water, followed by brine, then dried (Na2SO4) and concentrated in vacuo. The resulting residue was purified by column chromatography (Si-PCC, gradient 3-12% MeOH in DCM) affording 4-Benzyloxy-2-[2-(2-isopropyl-5-methyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,3a-diazabenzo[e]azulen-8-yloxy]-2-methylbutan-1-ol (29 mg, 98%). 1H NMR (CDCl3, 400 MHz): δ 8.41 (1H, d, J=8.83 Hz), 7.60 (1H, s), 7.39-7.27 (5H, m), 6.81 (1H, dd, J=8.83, 2.41 Hz), 6.69 (1H, d, J=2.37 Hz), 5.98-5.85 (1H, m), 4.60-4.50 (2H, m), 4.49-4.35 (4H, m), 3.83-3.69 (2H, m), 3.65-3.55 (2H, m), 3.24 (1H, s), 2.42 (3H, s), 2.20-2.12 (1H, m), 2.07-1.97 (1H, m), 1.57 (6H, d, J=6.75 Hz), 1.31 (3H, s)
