Reaction Steps
To a solution of aziridine 13 (16 mg; 0.05 mmol) in 3-pentanol (1 mL) was added Cu(OTf)2 (3 mg; 0.008 mmol). After 16 h the reaction mixture was quenched by addition of saturated solution of NaHCO3 (0.1 ml) and concentrated. Chromatography of residue [hexane-ethyl acetate (3:1)→(2:1), 4.5 ml silica] afforded 12 mg (60%) of compound 15 as white solid: m.p.=144-145° C. (CHCl3); RF=0.3 (ethyl acetate-hexane 1:2); [α]20D=−21.54 (c=0.5, CHCl3); IR (KBr, cm−1) ν 3324, 2976, 3966, 2933, 2877, 2855, 1720, 1687, 1658, 1587, 1536, 1459, 1384, 1297, 1250, 1176, 1146, 1130, 1086, 1054, 1019, 948; 1H NMR (CDCl3, 600 Mhz) δ 6.81 (s, 1H), 5.80 (d, J=9.6 Hz, 1H), 5.11 (d, J=9.0 Hz, 1H), 4.22 (m, 2H), 4.08 (ddd, J=2 x≈4.8, 9.3 Hz, 1H), 3.97 (m, 1H), 3.81 (ddd, J=5.1, 2×9.6 Hz, 1H), 3.37 (qui, J=5.7 Hz, 1H), 2.76 (dd, J=4.8, 17.7 Hz, 1H), 2.31 (m, 1H), 2.00 (s, 3H), 1.51 (m, 4H), 1.44 (s, 9H), 1.30 (t, J=7.2 Hz, 3H), 0.90 (m, 6H); 13C NMR (CDCl3, 150 Mhz) δ 170.85, 165.98, 156.35, 137.65, 129.34, 82.21, 79.73, 76.00, 61.00, 54.47, 49.00, 31.01, 28.33, 26.12, 25.69, 23.41, 14.20, 9.54, 9.21.
