Reaction Steps
Following the procedure as described in EXAMPLE 9 and making non-critical variations using 5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one to replace 3-methylspiro[furo[3,2-f][1,2]benzisoxazole-5,3′-indol]-2′(1H)-one, and 1-(benzyloxy)-3-(bromomethyl)benzene to replace 2-(bromomethyl)-5-(trifluoromethyl)furan, 1′-[3-(benzyloxy)benzyl]-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1H)-one was obtained (82%) as a colorless solid: mp 66-68° C.; 1H NMR (300 MHz, CDCl3) δ7.43-7.14 (m, 8H), 7.06-6.99 (m, 1H), 6.97-6.87 (m, 3H), 6.81-6.75 (m, 1H), 6.48 (s, 1H), 6.43 (s, 1H), 5.10-5.00 (m, 3H), 4.85-4.75 (m, 1H), 4.84 (ABq, 2H), 4.56-4.47 (m, 2H), 2.98-2.88 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 177.9, 161.8, 161.3, 159.2, 142.1, 137.4, 136.6, 132.7, 129.9, 128.7, 128.6, 128.0, 127.5, 123.8, 123.4, 120.2, 119.9 (2C), 118.8, 114.0, 113.9, 109.3, 93.2, 80.5, 72.3, 70.0, 57.7, 44.0, 29.0; MS (ES+) m/z 476.1 (M+1).
