558
A. Sandulache et al.
(s, H-3,4), 6.98 (d, J ¼ 8.8Hz, H-8), 7.43 (dd, J ¼ 8.8, 2.6 Hz, H-9), 7.89 (d, J ¼ 2.6 Hz, H-11) ppm;
13C NMR: ꢃ ¼ 22.8 (C-1), 30.4 (C-6), 45.1 (C-12a), 55.6 and 55.7 (2 OCH3), 77.8 (C-6a), 107.6 (C-3,
4), 119.6 (C-8), 121.5 (C-11a), 122.9 (C-1a), 124.1 (C-5a), 126.5 (C-11), 126.8 (C-10), 135.7 (C-9),
151.0 and 151.3 (C-2,5), 159.7 (C-7a), 192.7 (C-12) ppm; MS: m=z (%) ¼ 347 (12), 346 (Mþ ꢄ
,
37Cl,
45), 345 (32), 344 (Mþ ꢄ 35Cl, 100), 343 (10), 342 (9), 340 (16), 329 (9), 327 (13), 325 (25), 315 (9),
,
313 (30), 311 (24), 297 (19), 296 (15), 295 (41), 190 (21), 189 (51), 175 (17), 174 (16), 173 (12), 161
(8), 159 (17), 158 (13), 157 (21), 156 (8), 155 (48), 151 (35), 144 (7), 131 (10), 128 (8), 127 (9), 126
(11), 121, (12), 115 (25), 103 (9), 91 (10), 77 (14).
cis-2,5-Dimethoxy-10-chlorobenzo[b]-1,6,6a,12a-tetrahydroxanthone (5c, C19H17ClO4)
1
Yield: 142.7 mg (36%); mp 194–196ꢂC; H NMR: ꢃ ¼ 2.71 (dd, J ¼ 16.7, 10.7Hz, H-1), 2.87 (ddd,
J ¼ 10.7, 6.2, 2.5 Hz, H-12a), 2.93 (dd, J ¼ 19.0, 4.6Hz, H-6), 3.02 (dd, J ¼ 16.7, 6.2 Hz, H-1), 3.28
(dd, J ¼ 19.0, 3.2 Hz, H-6), 3.75 and 3.80 (2s, 2 OCH3), 4.93–4.96 (m, H-6a), 6.64 (AB, J ¼ 9.2 Hz,
H-3 or H-4), 6.68 (AB, J ¼ 9.2 Hz, H-4 or H-3), 6.90 (d, J ¼ 8.9 Hz, H-8), 7.39 (dd, J ¼ 8.9, 2.6Hz,
H-9), 7.87 (d, J ¼ 2.6Hz, H-11) ppm; 13C NMR: ꢃ ¼ 20.6 (C-1), 27.5 (C-6), 43.6 (C-12a), 55.5 and
55.6 (2 OCH3), 74.7 (C-6a), 107.3 (C-3,4), 119.7 (C-8), 120.2 (C-11a), 121.8 (C-1a), 123.9 (C-5a),
126.8 (C-11), 126.9 (C-10), 135.7 (C-9), 151.0 (C-2), 151.3 (C-5), 159.4 (C-7a), 194.0 (C-12) ppm;
MS: m=z (%) ¼ 347 (7), 346 (Mþ ꢄ
, ,
37Cl, 35), 345 (23), 344 (Mþ ꢄ 35Cl, 100), 325 (5), 313 (13), 311
(10), 297 (8), 295 (22), 190 (15), 189 (47), 175 (13), 174 (11), 164 (10), 159 (11), 158 (9), 157 (9), 155
(25), 151 (14), 149 (13), 121 (7), 115 (15), 103 (6), 91 (9), 83 (12), 77 (9).
trans-3,4-Dibromo-2,5-dimethoxybenzo[b]-1,6,6a,12a-tetrahydroxanthone (4d, C19H16Br2O4)
1
Yield 269.0mg (50%); mp 187–189ꢂC; H NMR: ꢃ ¼ 2.71 (dd, J ¼ 18.2, 12.0Hz, H-1), 2.91 (dd,
J ¼ 13.2, 12.0, 5.5 Hz, H-12a), 3.05 (ddd, J ¼ 17.0, 10.4, 1.2 Hz, H-6), 3.62 (dd, J ¼ 17.0, 5.8 Hz, H-6),
3.66 (dd, J ¼ 18.2, 5.5 Hz, H-1), 3.85 and 3.86 (2s, 2 OCH3), 4.54 (ddd, J ¼ 13.2, 10.4, 5.8 Hz, H-6a),
7.04 (d, J ¼ 8.3 Hz, H-8), 7.05–7.10 (m, H-10), 7.53 (ddd, J ¼ 8.3, 7.0, 1.7 Hz, H-9), 7.95 (dd, J ¼ 7.8,
1.7 Hz, H-11) ppm; 13C NMR: ꢃ ¼ 23.5 (C-1), 31.2 (C-6), 45.1 (C-12a), 60.1 and 60.2 (2 OCH3), 76.7
(C-6a), 117.8 (C-8), 118.9 (C-3,4), 120.6 (C-11a), 121.7 (C-10), 127.3 (C-11), 128.3 (C-5a), 129.4 (C-
1a), 136.2 (C-9), 152.4 and 152.6 (C-2,5), 160.9 (C-7a), 192.8 (C-12) ppm; MS: m=z (%) ¼ 471 (8),
470 (Mþ ꢄ 81Br, 36), 469 (19), 468 (60), 467 (14), 466 (Mþ ꢄ 79Br, 36), 453 (7), 451 (8), 449 (7), 439
, ,
(16), 438 (7), 437 (33), 436 (6), 435 (27), 426 (9), 425 (8), 424 (33), 423 (10), 422 (29), 421 (12), 420
(8), 419 (19), 393 (16), 391 (18), 375 (11), 373 (9), 309 (7), 253 (9), 225 (7), 207 (8), 188 (14), 173 (9),
160 (24), 159 (15), 145 (11), 122 (13), 121 (100), 120 (17), 115 (16), 114 (9), 105 (12), 102 (14), 93
(12), 92 (31), 77 (16), 76 (10).
cis-3,4-Dibromo-2,5-dimethoxybenzo[b]-1,6,6a,12a-tetrahydroxanthone (5d, C19H16Br2O4)
1
Yield: 231.4 mg (43%); mp 158–160ꢂC; H NMR: ꢃ ¼ 2.80–2.88 (m, H-1, 12a), 3.03 (dd, J ¼ 18.6,
4.9 Hz, H-6), 3.02–3.14 (m, H-1), 3.34 (dd, J ¼ 18.6, 3.6Hz, H-6), 3.76 and 3.84 (2s, 2 OCH3), 4.95
(bs, H-6a), 6.97 (d, J ¼ 8.0 Hz, H-8), 7.07 (dd, J ¼ 7.7, 7.6Hz, H-10), 7.51 (dd, J ¼ 8.0, 7.6 Hz, H-9),
7.93 (d, J ¼ 7.7 Hz, H-11) ppm; 13C NMR: ꢃ ¼ 21.3 (C-1), 28.3 (C-6), 43.7 (C-12a), 60.1 and 60.2
(2 OCH3), 73.8 (C-6a), 118.0 (C-8), 118.8 (C-3,4), 119.1 (C-11a), 121.8 (C-10), 127.5 (C-1a), 127.6
(C-11), 129.3 (C-5a), 136.3 (C-9), 152.3 and 152.7 (C-2,5), 160.6 (C-7a), 194.2 (C-12) ppm; MS: m=z
(%) ¼ 471 (13), 470 (Mþ ꢄ
, ,
81Br, 53), 469 (27), 468 (87), 467 (18), 466 (Mþ ꢄ 79Br, 53), 451 (6), 439
(11), 437 (26), 435 (21), 426 (16), 425 (14), 424 (51), 423 (13), 422 (43), 412 (11), 419 (16), 393 (13),
391 (17), 390 (10), 388 (9), 375 (11), 348 (7), 307 (9), 263 (8), 253 (9), 207 (8), 1898 (15), 173 (10),
160 (19), 150 (10), 145 (10), 129 (7), 122 (12), 121 (100), 115 (12), 104 (10), 102 (10), 92 (21), 85
(17), 83 (25).