Reaction Steps
Following the procedure as described in EXAMPLE 7.3 and making non-critical variations using (R)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one to replace (S)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one, (R)-1′-pentyl-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one was obtained (74%) as a colorless solid: 1H NMR (300 MHz, CDCl3) δ 7.25-7.30 (m, 1H), 7.16-7.11 (m, 1H), 6.99-7.04 (m, 1H), 6.89 (d, J=7.8 Hz, 1H), 6.47 (s, 1H), 6.19 (s, 1H), 4.73 (ABq, 2H), 4.20-4.06 (m, 4H), 3.86-3.59 (m, 2H), 1.82-1.63 (m, 2H), 1.42-1.28 (m, 4H), 0.89 (t, J=6.8 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ177.2, 155.2, 144.5, 142.4, 138.2, 132.5, 128.7, 123.9, 123.0, 121.2, 111.4, 108.5, 99.3, 80.1, 64.5, 63.9, 58.0, 40.3, 29.0, 27.1, 22.3, 14.0; MS (ES+) m/z 366.1 (M+1).
