Reaction Steps
Following the procedure as described in EXAMPLE 4 and making non-critical variations using 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, 1′-(tetrahydro-2H-pyran-2-ylmethyl)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one was obtained (45%) as a colorless solid: mp 158-166° C. (hexanes); 1H NMR (300 MHz, CDCl3) (diastereomers) δ7.31-7.25 (m, 1H), 7.13 (d, J=7.5 Hz, 1H), 7.08-7.00 (m, 2H), 6.48 (s, 1H), 6.24 (s, 0.5H), 6.22 (s, 0.5H), 4.89 (d, J=9.0 Hz, 0.5H), 4.88 (d, J=9.0 Hz, 0.5H), 4.64 (d, J=9.0 Hz, 0.5H), 4.63 (d, J=9.0 Hz, 0.5H), 4.21-4.16 (m, 2H), 4.14-4.09 (m, 2H), 4.01-3.93 (m, 1H), 3.91-3.82 (m, 1H), 3.74-3.63 (m, 2H), 3.44-3.33 (m, 1H), 1.91-1.81 (m, 1H), 1.68-1.31 (m, 5H); 13C NMR (75 MHz, CDCl3) (diastereomers) δ177.89, 177.80, 155.30, 155.27, 144.61, 143.25, 143.11, 138.34, 132.46, 132.35, 128.78, 128.73, 123.66, 123.64, 123.19, 123.17, 121.51, 121.45, 111.76, 111.62, 109.90, 109.77, 99.41, 99.36, 80.14, 75.75, 75.58, 68.57, 68.53, 64.63, 64.02, 58.08, 58.04, 45.83, 45.77, 29.70, 29.57, 25.88, 23.13; MS (ES+) m/z 394.2 (M+1); Anal. Calcd for C23H23NO5: C, 70.21; H, 5.89; N, 3.56. Found: C, 70.03; H, 5.97; N, 3.17.
