Reaction Steps
Following the procedure as described in EXAMPLE 4 and making non-critical variations using 2-(trifluoromethyl)benzyl bromide to replace 2-(bromomethyl)tetrahydro-2H-pyran, and (8S)-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, (8S)-1′-[2-(trifluoromethyl)benzyl]-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one was obtained (82%) as a colorless solid: mp 137-138° C. (diethyl ether); 1H NMR (300 MHz, CDCl3) δ 7.72 (d, J=7.7 Hz, 1H), 7.52-7.33 (m, 2H), 7.22-7.12 (m, 3H), 7.07-7.00 (m, 1H), 6.61 (d, J=7.7 Hz, 1H), 6.52 (s, 1H), 6.31 (s, 1H), 5.26 (d, J=17.1 Hz, 1H), 5.07 (d, J=17.1 Hz, 1H), 4.97 (d, J=8.9 Hz, 1H), 4.70 (d, J=8.9 Hz, 1H), 4.23-4.09 (m, 4H); 13C NMR (75 MHz, CDCl3) δ 177.9, 155.4, 144.8, 141.8, 138.4, 133.9, 132.5, 132.1, 129.0, 127.9 (q, 2JC-F=30.8 Hz), 127.6, 126.8, 126.4 (q, 5JC-F=5.8 Hz), 124.4 (q, 1JC-F=273.8 Hz), 124.1, 123.8, 120.8, 111.6, 109.2, 99.6, 80.3, 64.5, 64.0, 58.2, 40.6 (q, J=3.4 Hz); MS (ES+) m/z 454.0 (M+1); Anal. Calcd. for C25H18F3NO4: C, 66.22; H, 4.00; N, 3.09. Found: C, 66.06; H, 3.98; N, 3.12.
