Reaction Steps
The product, obtained as a yellow oil, was prepared from (3S,3aR,5R)-5-[(benzyloxy)methyl]-3-methyl-3,3a,4,5-tetrahydro-7H-pyrano[3,4-c][1,2]oxazole (C16) according to the general procedure for the synthesis of (3aR,5R,7aS)-5-[(benzyloxy)methyl]-7a-(2,4-difluorophenyl)hexahydro-1H-pyrano[3,4-c][1,2]oxazole (C5) in Preparation P1. Yield: 21.5 g, 57.2 mmol, 48%. LCMS m/z 376.2 [M+H+]. 1H NMR (400 MHz, CDCl3) δ 7.98 (ddd, J=9.1, 9.1, 6.8 Hz, 1H), 7.28-7.40 (m, 5H), 6.87-6.93 (m, 1H), 6.80 (ddd, J=11.9, 8.6, 2.6 Hz, 1H), 4.60 (AB quartet, JAB=12.1 Hz, ΔνAB=19.9 Hz, 2H), 3.99-4.06 (m, 1H), 3.97 (dd, half of ABX pattern, J=12.9, 2.0 Hz, 1H), 3.80-3.88 (m, 2H), 3.56 (dd, half of ABX pattern, J=10.2, 6.3 Hz, 1H), 3.49 (dd, half of ABX pattern, J=10.2, 4.1 Hz, 1H), 2.81-2.87 (m, 1H), 2.04 (ddd, J=14.2, 7.6, 2.8 Hz, 1H), 1.48-1.59 (m, 1H), 0.79 (d, J=6.4 Hz, 3H).
