Reaction Steps
Following the procedure as described in EXAMPLE 2 and making non-critical variations using 3-(6-hydroxy-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-7-yl)-1-[(2R)-tetrahydrofuran-2-ylmethyl]-1,3-dihydro-2H-indol-2-one trifluoroacetate to replace 1-(diphenylmethyl)-3-(2-hydroxy-4-methoxy-5-methylphenyl)-1,3-dihydro-2H-indol-2-one, 4-methyl-1′-[(2R)-tetrahydrofuran-2-ylmethyl]-3,4-dihydro-2H-spiro[furo[2,3-g][1,4]benzoxazine-8,3′-indol]-2′(1′H)-one was obtained (62%) as a pale yellow solid: mp 138-140° C. (diethyl ether/hexanes); 1H NMR (300 MHz, CDCl3) (diastereomers) δ7.26 (dd, J=7.7, 7.7 Hz, 1H), 7.16-6.99 (m, 3H), 6.29 (s, 1H), 6.122, 6.117 (s, 1H), 4.86 (d, J=8.9 Hz, 1H), 4.61 (d, J=8.9 Hz, 1H), 4.31-4.21 (m, 1H), 4.13 (dd, J=4.5, 4.5 Hz, 2H), 3.99-3.66 (m, 4H), 3.23 (dd, J=4.5, 4.2 Hz, 2H), 2.87 (s, 3H), 2.07-1.83 (m, 3H), 1.81-1.67 (m, 1H); 13C NMR (75 MHz, CDCl3) (diastereomers) δ178.5, 178.3, 156.1, 143.1, 142.9, 139.0, 137.8, 132.7, 132.6, 128.7, 128.6, 123.84, 123.76, 123.2, 116.41, 116.35, 110.26, 110.22, 109.7, 109.4, 94.4, 80.2, 80.1, 77.3, 76.8, 68.38, 68.35, 64.5, 58.3, 49.2, 44.64, 44.58, 39.0, 29.4, 29.0, 25.9, 25.7; MS (ES+) m/z 393.0 (M+1).
