Reaction Steps
Following the procedure as described in EXAMPLE 4 and making non-critical variations using 2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one to replace 5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2″(1′H)-one, and 4-(bromomethyl)tetrahydro-2H-pyran to replace 2-(bromomethyl)tetrahydro-2H-pyran, 1′-(tetrahydro-2H-pyran-4-ylmethyl)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one was obtained (95%) as a colorless solid: mp 129-131° C. (hexanes); 1H NMR (300 MHz, CDCl3) δ7.29 (ddd, J=7.9, 7.9, 1.3 Hz, 1H), 7.16 (d, J=7.5 Hz, 1H), 7.04 (ddd, J=7.4, 7.4, 1.0 Hz, 1H), 6.89 (d, J=8.1 Hz, 1H), 6.50 (s, 1H), 6.18 (s, 1H), 4.87 (d, J=8.9 Hz, 1H), 4.62 (d, J=8.9 Hz, 1H), 4.22-4.16 (m, 2H), 4.15-4.09 (m, 2H), 4.03-3.94 (m, 2H), 3.74 (dd, J=13.8, 7.7 Hz, 1H), 3.55 (dd, J=13.8, 7.1 Hz, 1H), 3.42-3.30 (m, 2H), 2.20-2.03 (m, 1H), 1.66-1.56 (m, 2H), 1.53-1.40 (m, 2H); 13C NMR (75 MHz, CDCl3) δ177.8, 155.4, 144.7, 142.8, 138.4, 132.5, 128.9, 124.2, 123.4, 121.1, 111.5, 108.7, 99.5, 80.4, 67.6, 67.5, 64.6, 64.0, 58.1, 46.2, 34.0, 30.93, 30.86; MS (ES+) m/z 394.2 (M+1); Anal. Calcd for C23H23NO5: C, 70.21; H, 5.89; N, 3.56. Found: C, 70.15; H, 5.92; N, 3.20.
