Reaction Steps
Following the procedure as described in EXAMPLE 4 and making non-critical variations using (S)-(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 2-(bromomethyl)-5-(trifluoromethyl)furan to replace 2-(bromomethyl)tetrahydro-2H-pyran, (S)-1′-{[5-(trifluoromethyl)furan-2-yl]methyl}-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 53-56° C. (methanol/water); 1H NMR (300 MHz, CDCl3) δ7.30 (dd, J=7.8, 7.8 Hz, 1H), 7.18 (d, J=7.2 Hz, 1H), 7.08 (dd, J=7.5, 7.5 Hz, 1H), 6.99 (d, J=8.1 Hz, 1H), 6.74 (dd, J=2.1, 0.9 Hz, 1H), 6.50 (s, 1H), 6.38 (d, J=3.0 Hz, 1H), 6.19 (s, 1H), 5.06 (d, J=16.2 Hz, 1H), 4.90 (d, J=9.0 Hz, 1H), 4.89 (d, J=16.2 Hz, 1H), 4.64 (d, J=9.0 Hz, 1H), 4.22-4.17 (m, 2H), 4.14-4.09 (m, 2H); 13C NMR (75 MHz, CDCl3) δ177.2, 155.3, 152.2, 144.8, 141.8 (q, J=43.0 Hz), 141.5, 138.5, 132.2, 129.1, 124.2, 123.9, 120.9, 118.9 (q, J=267 Hz), 112.8 (q, J=2.8 Hz), 111.6, 109.3, 109.0, 99.5, 80.1, 64.6, 64.0, 58.1, 37.1; MS (ES+) m/z 443.9 (M+1).
