Reaction Steps
1H NMR syn (CDCl3) δ=1.28 (t, 3H, J=7.1 Hz), 1.29 (d, 3H, J=7.1 Hz), 3.35 (br, 1H), 3.84-3.96 (m, 4H), 4.27 (q, 2H, J=7.1 Hz), 4.58 (t, 1H, J=4.2 Hz), 6.96 (apparent d, 2H, J=9.0 Hz), 7.30-7.45 (m, 5H) 7.95 (apparent d, 2H, J=8.8 Hz); anti (CDCl3) δ=1.19 (t, 3H, J=7.1 Hz), 1.36 (d, 3H, J=7.3 Hz), 3.75 (d, 1H, J=9.3 Hz), 3.88 (s, 3H), 3.94 (dq, 1H, J=4.6, 7.3 Hz), 4.15 (apparent dq, 2H, J=3.2, 7.1 Hz), 4.36 (dd, 1H, J=4.6, 9.3 Hz), 6.92-6.99 (m, 2H), 7.90-7.97 (m, 2H); 13C NMR syn (CDCl3) δ=12.3, 14.0, 43.7, 55.4, 61.8, 71.7, 113.9, 128.5, 130.7, 163.7, 173.1, 200.4; anti (CDCl3) δ=14.0, 14.6, 43.2, 55.5, 61.4, 73.4, 113.9, 128.7, 130.8, 163.8, 173.2, 201.9; IR (neat) syn 3477, 2979, 2935, 2850, 1730, 1670, 1600, 1573, 1510, 1463, 1420, 1308, 1261, 1173, 1125, 1027, 976, 843, 770, 604; anti 3478, 2979, 2941, 2843, 1738, 1671, 1599, 1580, 1510, 1457, 1419, 1370, 1308, 1257, 1216, 1172, 1092, 1026, 974, 841 cm−1; HRMS (FAB); Exact mass calcd for C14H19O5 [M+H]+, 267.1232, Found 267.1232.; HPLC, Daicel Chiralcel ADH, hexane/iPrOH=4/1, flow rate=0.2 mL/min: tR=60.5 min (2R, 3R), tR=65.4 min (2S, 2S), tR=75.2 min (2R, 3S), tR=78.9 min (2S, 3R).
