LETTER
by thin layer chromatograph. After completion of the
Clean Synthesis of 1,8-Dioxo-octahydroxanthene Derivatives
869
(s, 6 H, 2 × CH3), 2.22 (dd, 4 H, J = 1.6 Hz, J = 3.6 Hz,
reactions, the mixture was cooled to r.t. and solid was
filtered off and washed with H2O (40 mL) and the crude
products isolated. The crude products were purified by
recrystallization by EtOH (95%). Data of the compounds are
shown below:
Compound 3a, 3,3,6,6-Tetramethyl-9-benzene-1, 8-
dioxo-octahydroxanthene. Mp 202–204 °C (from EtOH).
IR (KBr): nmax = 3030, 2980, 1685, 1670, 1470, 1360, 1200,
1170, 1140, 1005, 740, 700 cm–1. 1H NMR (CDCl3): d = 098
(s, 6 H, 2 × CH3), 1.12 (s, 6 H, 2 × CH3), 2.20 (dd, 4 H,
J = 1.6 Hz, J = 2.4 Hz, 2 × CH2, H-4, H-5), 2.45 (s, 4 H,
2 × CH2, H-2, H-7), 4.66 (s, 1 H, H-9), 7.21 (m, 5 H, Ar-H).
Anal. Calcd for C23H26O3: C, 78.83; H, 7.47. Found: C,
78.95; H, 7.42.
2 × CH2, H-4, H-5), 2.53 (s, 4 H, 2 × CH2, H-2, H-7), 4.85 (s,
1 H, H-9), 7.43 (s, 1 H, ArH), 7.88–7.95 (m, 3 H, ArH).
Anal. Calcd for C23H25NO5: C, 69.85; H, 6.37; N, 3.54.
Found: C, 69.90; H, 6.50; N, 3.42.
Compound 3h, 3,3,6,6-Tetramethyl-9-(4-nitrophenyl)-
1,8-dioxo-octahydroxanthene. Mp 226–228 °C (from
EtOH). IR (KBr): nmax = 3030, 2980, 1665, 1650, 1623,
1530, 1360, 1340, 1200, 1070, 1042, 1005, 875, 833 cm–1.
1H NMR (CDCl3): d = 1.00 (s, 6 H, 2 × CH3), 1.12 (s, 6 H,
2 × CH3), 2.16 (dd, 4 H, J = 1.6 Hz, J = 3.6 Hz, 2 × CH2, H-
4, H-5), 2.41 (s, 4 H, 2 × CH2, H-2, H-7), 4.46 (s, 1 H, H-9),
7.50–7.63 (m, 2 H, ArH), 8.06–8.16 (m, 2 H, ArH). Anal.
Calcd for C23H25NO5: C, 69.85; H, 6.37; N, 3.54. Found: C,
69.89; H, 6.46; N, 3.40.
Compound 3b, 3,3,6,6-Tetramethyl-9-(4-chlorophenyl)-
1,8-dioxo-octahydroxanthene. Mp 228–230 °C (from
EtOH). IR (KBr): nmax = 3025, 2980, 1680, 1660, 1620,
1490, 1480, 1360, 1200, 1170, 1140, 1090, 1010, 1000, 850,
840 cm–1. 1H NMR (CDCl3): d = 0.98 (s, 6 H, 2 × CH3), 1.10
(s, 6 H, 2 × CH3), 2.23 (dd, 4 H, J = 1.6 Hz, J = 3.6 Hz,
2 × CH2, H-4, H-5), 2.50 (s, 4 H, 2 × CH2, H-2, H-7), 4.64 (s,
1 H, H-9), 7.26–7.43 (m, 4 H, ArH). Anal. Calcd for
C23H25ClO3: C, 71.77; H, 6.54. Found: C, 71.89; H, 6.45.
Compound 3c, 3,3,6,6-Tetramethyl-9-(3-chlorophenyl)-
1,8-dioxo-octahydroxanthene. Mp 183–184 °C (from
EtOH). IR (KBr): nmax = 3030, 2980, 1685, 1660, 1620,
1490, 1475, 1365, 1200, 1170, 1135, 1095, 1000, 850, 840
cm–1. 1H NMR (CDCl3): d = 1.02 (s, 6 H, 2 × CH3), 1.12 (s,
6 H, 2 × CH3), 2.30 (dd, 4 H, J = 1.6 Hz, J = 3.6 Hz,
2 × CH2, H-4, H-5), 2.49 (s, 4 H, 4 × CH2, H-2, H-7), 4.74 (s,
1 H, H-9), 7.11–7.25 (m, 4 H, ArH). Anal. Calcd for
C23H25ClO3: C, 71.77; H, 6.54. Found: C, 71.92; H, 6.41.
Compound 3d, 3,3,6,6-Tetramethyl-9-(2-chlorophenyl)-
1,8-dioxo-octahydroxanthene. Mp 228–230 °C (from
EtOH). IR (KBr): nmax = 3030, 2980, 1680, 1665, 1620,
1495, 1470, 1360, 1200, 1170, 1140, 1100, 1000, 850, 840
cm–1. 1H NMR (CDCl3): d = 0.98 (s, 6 H, 2 × CH3), 1.10 (s,
6 H, 2 × CH3), 2.06 (dd, 4 H, J = 1.6 Hz, J = 3.0 Hz,
2 × CH2, H-4, H-5), 2.49 (s, 4 H, 2 × CH2, H-2, H-7), 4.64 (s,
1 H, H-9), 7.26–7.35 (m, 4 H, ArH). Anal. Calcd for
C23H25ClO3: C, 71.77; H, 6.54. Found: C, 71.88; H, 6.35.
Compound 3e, 3,3,6,6-Tetramethyl-9-(2,4-
dichlorophenyl)-1,8-dioxo-octahydroxanthene. Mp 253–
254 °C (from EtOH). IR (KBr): nmax = 3035, 2980, 1685,
1660, 1633, 1490, 1480, 1410, 1360, 1210, 1195, 1155,
1100, 1000, 850, 770 cm–1. 1H NMR (CDCl3): d = 1.03 (s, 6
H, 2 × CH3), 1.12 (s, 6 H, 2 × CH3), 2.21 (dd, 4 H, J = 1.6
Hz, J = 3.2 Hz, 2 × CH2, H-4, H-5), 2.46 (s, 4 H, 2 × CH2, H-
2, H-7), 4.96 (s, 1 H, H-9), 7.18 (s, 1 H, ArH), 7.39 (d, 2 H,
J = 8.4 Hz, ArH). Anal. Calcd for C23H24Cl2O3: C, 65.87; H,
5.73. Found: C, 65.96; H, 5.59.
Compound 3f, 3,3,6,6-Tetramethyl-9-(2-nitrophenyl)-
1,8-dioxo-octahydroxanthene. Mp 247–249 °C (from
EtOH). IR (KBr): nmax = 3035, 2980, 1685, 1673, 1620,
1533, 1360, 1211, 1173, 1152, 1010, 860, 800, 780, 745, 703
cm–1. 1H NMR (CDCl3): d = 0.99 (s, 6 H, 2 × CH3), 1.12 (s,
6 H, 2 × CH3), 2.16 (dd, 4 H, J = 1.6 Hz, J = 3.6 Hz,
2 × CH2, H-4, H-5), 2.41 (s, 4 H, 2 × CH2, H-2, H-7), 5.61 (s,
1 H, H-9), 7.36–7.45 (m, 4 H, ArH). Anal. Calcd for
C23H25NO5: C, 69.85; H, 6.37; N, 3.54. Found: C, 69.93; H,
6.54; N, 3.36.
Compound 3i, 3,3,6,6-Tetramethyl-9-(4-hydroxy-
phenyl)-1,8-dioxo-octahydroxanthene. Mp 246–248 °C
(from EtOH). IR (KBr): nmax = 3360, 3025, 2980, 1795,
1725, 1700, 1633, 1613, 1525, 1390, 1375, 1260, 1233,
1200, 1196, 850, 843 cm–1. 1H NMR (CDCl3): d = 0.99 (s, 6
H, 2 × CH3), 1.10 (s, 6 H, 2 × CH3), 2.13 (dd, 4 H, J = 1.6
Hz, J = 4.0 Hz, 2 × CH2, H-4, H-5), 2.47 (s, 4 H, 2 × CH2, H-
2, H-7), 4.62 (s, 1 H, H-9), 6.77 (d, 2 H, J = 8.0 Hz, ArH),
6.98 (d, 2 H, J = 8.0, ArH). Anal. Calcd for C23H26O4: C,
75.38; H, 7.15. Found: C, 75.26; H, 7.09.
Compound 3j, 3,3,6,6-Tetramethyl-9-(4-methoxy-
phenyl)-1,8-dioxo-octahydroxanthene. Mp 242–244 °C
(from EtOH). IR (KBr): nmax = 3025, 2980, 1685, 1660,
1620, 1513, 1450, 1375, 1360, 1260, 1235, 1170, 1142,
1032, 1003, 840 cm–1. 1H NMR (CDCl3): d = 1.01 (s, 6 H,
2 × CH3), 1.09 (s, 6 H, 2 × CH3), 2.20 (dd, 4 H, J = 1.6 Hz,
J = 2.0 Hz, 2 × CH2, H-4, H-5), 2.46 (s, 4 H, 2 × CH2, H-2,
H-7), 3.73 (s, 3 H, CH3O), 4.70 (s, 1 H, H-9), 6.67–7.28 (m,
4 H, ArH). Anal. Calcd for C24H28O4: C, 75.76; H, 7.41.
Found: C, 75.85; H, 7.31.
Compound 3k, 3,3,6,6-Tetramethyl-9-(4-dimethyl-
aminophenyl)-1,8-dioxo-octahydroxanthene. Mp 226-
228 °C (from EtOH). IR (KBr): nmax = 3035, 2980, 2195,
1687, 1665, 1580, 1500, 1454, 1400, 1234, 1195, 1040, 811,
743 cm–1. 1H NMR (CDCl3): d = 1.02 (s, 6 H, 2 × CH3), 1.11
(s, 6 H, 2 × CH3), 2.21 (dd, 4 H, J = 1.6 Hz, J = 2.4 Hz,
2 × CH2, H-4, H-5), 2.46 (s, 4 H, 2 × CH2, H-2, H-7), 2.88 [s,
6 H, -N(CH3)2], 4.67 (s, 1 H, H-9), 6.62 (s, 2 H, ArH), 7.15
(s, 2 H, ArH). Anal. Calcd for C25H31NO3: C, 76.34; H, 7.89;
N, 3.56. Found: C, 76.48; H, 7.86; N, 3.43.
Compound 3l, 3,3,6,6-Tetramethyl-9-(4-methylphenyl)-
1,8-dioxo-octahydroxanthene. Mp 217–218 °C (from
EtOH). IR (KBr): nmax = 3035, 2980, 1685, 1665, 1633,
1515, 1470, 1365, 1200, 1165, 1140, 790, 775cm–1. 1H NMR
(CDCl3): d = 1.03 (s, 6 H, 2 × CH3), 1.12 (s, 6 H, 2 × CH3),
2.07 (dd, 4 H, J = 1.6 Hz, J = 2.4 Hz, 2 × CH2, H-4, H-5),
2.40 (s, 4 H, 2 × CH2, H-2, H-7), 2.43 (s, 3 H, CH3Ar), 4.69
(s, 1 H, H-9), 6.80–7.28 (m, 4 H, ArH). Anal. Calcd for
C24H28O3: C, 79.08; H, 7.74. Found: C, 79.25; H, 7.59.
Compound 3m, 3,3,6,6-Tetramethyl-9-(4-hydroxy-3-
methoxyphenyl)-1,8-dioxo-octahydrox-anthene. Mp
226–228 °C (from EtOH). IR (KBr): nmax = 3443, 3030,
2985, 2195, 1687, 1660, 1580, 1500, 1454, 1400, 1234,
1195, 1040, 811, 743 cm–1. 1H NMR (CDCl3): d = 1.02 (s, 6
H, 2 × CH3), 1.12 (s, 6 H, 2 × CH3), 2.24 (d, 4 H, J = 3.6 Hz,
2 × CH2, H-4, H-5), 2.47 (s, 4 H, 2 × CH2, H-2, H-7), 3.91 (s,
3 H, OCH3), 4.68 (s, 1 H, H-9), 5.49 (s, 1 H, OH), 6.60 (s, 1
H, ArH), 6.74 (s, 1 H, ArH), 7.03 (s, 1 H, ArH). Anal. Calcd
for C24H28O5: C, 77.84; H, 7.57. Found: C, 77.98; H, 7.43.
Compound 3n, 3,3,6,6-Tetramethyl-9-(3,4-dioxy-
methylenephenyl)-1,8-dioxo-octahydrox-anthene. Mp
224–226 °C (from EtOH). IR (KBr): nmax = 3030, 2980,
Compound 3g, 3,3,6,6-Tetramethyl-9-(3-nitrophenyl)-
1,8-dioxo-octahydroxanthene. Mp 168–170 °C (from
EtOH). IR (KBr): nmax = 3030, 2980, 1680, 1675, 1625,
1535, 1365, 1335, 1210, 11750, 1145, 1006, 830, 765, 730,
700 cm–1. 1H NMR (CDCl3): d = 1.02 (s, 6 H, 2 × CH3), 1.13
Synlett 2004, No. 5, 866–870 © Thieme Stuttgart · New York