Reaction Steps
Following the procedure described in EXAMPLE 9 and making non-critical variations using (8S)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one to replace 3-methylspiro[furo[3,2-f][1,2]benzisoxazole-5,3′-indol]-2′(1′H)-one, and 4-benzyloxybenzyl chloride to replace 2-(bromomethyl)-5-(trifluoromethyl)furan, (8S)-1′-[4-(benzyloxy)benzyl]-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 151-153° C.; 1H NMR (300 MHz, DMSO-d6) δ7.45-7.23 (m, 8H), 7.18-7.14 (m, 1H), 7.05-6.97 (m, 4H), 6.53 (s, 1H), 6.06 (s, 1H), 5.07 (s, 2H), 4.86 (ABq, J=27.9, 15.6 Hz, 2H), 4.73 (ABq, J=39.9, 9.3 Hz, 2H), 4.22-4.07 (m, 4H); 13C NMR (75 MHz, DMSO-d6) δ 176.6, 157.7, 154.6, 144.1, 142.1, 137.8, 136.9, 131.7, 128.7, 128.6, 128.4, 128.3, 127.8, 127.6, 123.5, 122.9, 121.2, 114.9, 110.8, 109.4, 98.8, 79.4, 69.1, 64.1, 63.5, 57.2, 42.4; MS (ES+) m/z 491.8 (M+1).
