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 3,5-dimethoxybenzyl bromide to replace 2-(bromomethyl)tetrahydro-2H-pyran, 1′(3,5-dimethoxybenzyl)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one was obtained (97%) as a colorless solid: mp 192-195° C. (diethyl ether/hexanes); 1F1 NMR (300 MHz, CDCl3) δ7.23-7.15 (m, 2H), 7.02 (dd, J=7.5, 7.5 Hz, 1H), 6.81 (d, J=7.5 Hz, 1H), 6.51 (s, 1H), 6.47 (d, J=1.8 Hz, 2H), 6.37 (t, J=1.8 Hz, 1H), 6.25 (s, 1H), 5.04 (d, J=15.5 Hz, 1H), 4.95 (d, J=9.0 Hz, 1H), 4.72 (d, J=15.5 Hz, 1H), 4.68 (d, J=9.0 Hz, 1H), 4.22-4.16 (m, 2H), 4.14-4.09 (m, 2H), 3.76 (s, 6H); 13C NMR (75 MHz, CDCl3) δ177.7, 161.3, 155.4, 144.7, 142.2, 138.5, 138.2, 132.3, 129.0, 123.9, 123.5, 121.2, 111.6, 109.5, 105.4, 99.8, 99.6, 80.2, 64.6, 64.0, 58.2, 55.5, 44.3; MS (ES+) m/z 446.0 (M+1).
