反应详情

The title compound was prepared according to the general procedure from ethyl trans-4-oxo-2-butenoate and trans-N-(4-methoxybenzenesulfonyl)-3-phenyprop-2-ene-1-imine using 10 mol % 9 as the catalyst in 90% yield as a white solid. [α]D20 (c 1.19, CHCl3)=+105.2; mp=111-113° C.; 1H NMR (400 MHz, CDCl3) δ 8.04 (dd, 2H, J=7.0, 2.1 Hz), 7.16-7.12 (m, 2H), 7.06-6.99 (m, 4H), 6.58 (dd, 2H, J=8.0, 1.1 Hz), 5.60 (dd, 1H, J=8.0, 6.5 Hz), 4.18-4.08 (m, 2H), 3.92 (s, 3H), 3.65 (t, 1H, J=6.9 Hz), 3.55-3.53 (m, 1H), 2.57 (dd, 1H, J=17.3, 6.1 Hz), 1.94 (dd, 1H, J=17.3, 7.5 Hz), 1.21 (t, 3H, J=7.0 Hz); 13C NMR (100 MHz, CDCl3) δ 171.7, 169.0, 164.3, 136.8, 131.4, 129.2, 128.9, 127.9, 127.9, 124.6, 114.3, 113.6, 61.0, 56.0, 44.1, 42.0, 31.6, 14.3; IR (thin film) ν 3086, 2982, 1720, 1594, 1496, 1454, 1406, 1367, 1264, 1132, 1091, 1026 cm−1; HRMS (ESI) calcd for C22H23NO6S [M+Na]+ 452.1138, found 452.1160; >99% ee (3R,4R)-isomer as determined by HPLC (AS-H, 9:1 hexanes/i-PrOH), tr (3S,4S)=53.9 min, tr (3R,4R)=39.2 min. For the (3R,4R) enantiomer (Table 2, entry 2), [α]D20 (c 0.98, CHCl3)=−112.7.