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 3,4-dimethoxybenzyl bromide (Oguri, T., et al., Chem. Pharm. Bull. (1977), 25:2287-91) to replace 2-(bromomethyl)tetrahydro-2H-pyran, 1′-(3,4-dimethoxybenzyl)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1H)-one was obtained (100%) as a colorless solid: mp 209-211° C. (hexanes/diethyl ether); 1H NMR (300 MHz, CDCl3) δ7.23-7.14 (m, 2H), 7.01 (dd, J=7.5, 7.5 Hz, 1H), 6.92-6.80 (m, 4H), 6.51 (s, 1H), 6.21 (s, 1H), 5.09 (d, J=15.3 Hz, 1H), 4.94 (d, J=9.0 Hz, 1H), 4.68 (d, J=15.3 Hz, 1H), 4.67 (d, J=9.0 Hz, 1H), 4.22-4.16 (m, 2H), 4.13-4.08 (m, 2H), 3.86 (s, 3H), 3.84 (s, 3H); 13C NMR (75 MHz, CDCl3) δ177.7, 155.3, 149.5, 148.8, 144.7, 142.2, 138.4, 132.4, 128.9, 128.4, 124.0, 123.5, 121.3, 120.0, 111.5, 111.2, 110.5, 109.5, 99.6, 80.1, 64.6, 64.0, 58.2, 56.02, 55.99, 44.1; MS (ES+) m/z 446.0 (M+1).
