Helvetica Chimica Acta ± Vol. 82 (1999)
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(d, C(4)); 130.63 (d, C(8)); 130.39 (d, C(10)); 129.41, 129.25, 128.65, 128.45 (4d, 8 C of 2 Ph); 126.92 (d, C(5));
126.00 (s, C(6a)); 124.57 (s, C(3)); 52.51 (t, CH2); 25.01 (q, Me C(11)); 24.20 (q, Me C(6)); 23.64
.
(q, Me C(9)); 19.88 (q, Me C(7)). EI-MS: 557(19), 556 (49, M ), 417(12), 416(32), 415 (100, [M
PhSO2] ), 275(35), 260(11), 259(19), 216(11), 215(17), 77 (18, [Ph] ). Anal. calc. for C32H28O5S2 (556.70):
C 69.04, H 5.07, S 11.52; found: C 68.71, H 5.08, S 11.25.
2.2.1. Formation of 4-Butyl-2,4-dihydro-6,7,9,11-tetramethyl-2-(phenylsulfonyl)-3-[(phenylsulfonyl)meth-
yl]cyclopenta[a]heptalen-1(1H)-one (13) from 6 in the Presence of BuLi. MeSO2Ph (0.034 g, 0.22 mmol) was
lithiated in THF as described above. At 788, 6 (0.028 g, 0.05 mmol) was added. After 30 min stirring at 208,
1.6m BuLi soln. (0.5 ml, 0.80 mmol) was added, followed by 1 h stirring at ambient temp. Usual workup,
followed by chromatography (silica gel (30 g); hexane/Et2O 2 : 1), led to a mixture (0.064 g) of MeSO2Ph and 13
with a content of ca. 25% of the latter. The mixture was chromatographed anew, and 13 was further purified by
recrystallization from Et2O/hexane (0.015 g, 48%).
Data of 13: Yellow needles. M.p. 2318. Rf (AcOEt/hexane 1:2) 0.38. IR (KBr): 3407w, 3059w, 2961m,
2923m, 2857w, 1711vs (CO), 1627w, 1570s, 1462w, 1446s, 1404w, 1378w, 1308vs, 1242m, 1187s, 1146vs, 1132s,
1082s, 1023w, 999w, 938w, 885w, 843m, 809w, 774m, 762m, 739w, 714w, 704m, 687s, 645w, 622w, 596m, 552s, 522w,
510w, 498w, 453w. 1H-NMR (600 MHz, CDCl3): 7.97 ± 7.95 (m, 2 arom. H); 7.72 (t, 3J 7.5, 1 arom. H); 7.62
(t, 3J 7.8, 2 arom. H); 7.55 ± 7.53 (m, 2 arom. H); 7.50 ± 7.47 (m, 1 arom. H); 7.29 ± 7.27 (m, 3 arom. H); 6.18
(s, H C(10)); 6.08 (s, H C(8)); 5.46 (dd, 3J 8.3, 4J 1.2, H C(5)); 4.94, 4.18 (AB, 2JAB 14.1, PhSO2CH2);
4.50 (s, H C(2)); 3.27 ± 3.22 (m, H C(4)); 2.11 (s, Me C(11)); 2.10 (s, Me C(9)); 1.89 (s, Me C(7)); 1.70
(d, 4J 1.2, Me C(6)); 1.35 ± 1.15 (m, 5 H of Bu); 0.89 (t, 3J 6.9, Me of Bu); 0.78 ± 0.72 (m, 1 H of Bu).
13C-NMR (150 MHz, CDCl3): 190.05 (s, CO); 154.67 (s, C(3a)); 146.93 (s, C(11a)); 139.44 (s, 1 C-atom of
Ph); 139.29 (s, C(6)); 138.69 (d, C(9)); 136.52 (s, 1 C of Ph); 134.07 (d, 1 C of Ph); 133.58 (d, 1 C of Ph); 132.37
(d, C(7)); 132.32 (s, C(11a)); 129.40 (d, 2 C of Ph); 129.34 (d, C(8)); 129.32 (s, C(6a)); 129.20 (d, 2 C of Ph);
128.52 (d, 2 C of Ph); 128.31 (d, 2 C of Ph); 127.80 (s, C(11b)); 127.04 (s, C(10)); 126.27 (d, C(5)); 115.73
(s, C(11)); 73.91 (d, C(2)); 54.05 (s, C(3)); 36.92 (d, C(4)); 33.27 (t, PhSO2CH2); 30.01 (t, MeCH2(CH2)2); 24.60
(q, Me C(9)); 23.35 (q, Me C(11)); 23.30 (q, Me C(6)); 22.77 (t, MeCH2(CH2)2); 20.90 (q, Me C(7));
14.00 (q, MeCH2(CH2)2). Anal. calc. for C36H38O5S2 (614.82): C 70.33, H 6.23; found: C 70.38, H 6.18.
The structure of 13 was finally established by an X-ray crystal-structure analysis (see Fig. 2 as well as
Sect. 4).
2.3. Formation of 7,8,10,12-Tetramethyl-3-(phenylsulfonyl)benzo[a]heptalene-2,4-diol (2b) and 5,11b-
Dihydro-3-hydroxy-6,7,9,11-tetramethyl-2-(phenylsulfonyl)-11b-[(phenylsulfonyl)methyl]cyclopenta[a]heptalen-
1(1H)-one (9). MeSO2Ph (0.681 g, 4.36 mmol) in THF (20 ml) was lithiated at 108 with 1.6m BuLi (2.7 ml,
4.36 mmol) and stirred for 0.5 h. Then, at 788, a soln. of 1'b (0.356 g, 1.09 mmol) was added dropwise. After
1 h stirring at 788, the temp. was raised within 1.5 h to 108. TLC control showed that all 1'b as well as its
monosubstitution product 4' had been consumed. Further 1.6m BuLi (2.7 ml, 4.36 mmol) was added within
5 min whereby the color of the mixture changed from orange via dark-red to dark-yellow. Cooling was removed,
and the mixture stirred for 15 h at r.t. Usual workup led to a residue that was chromatographed (silica gel
(120 g); hexane/Et2O 2 : 1). The first fraction delivered 2b (0.235 g, 50%) as yellow crystals. A second fraction
(0.314 g, ca. 44%) contained 9, which was recrystallized from CH2Cl2/Et2O/hexane to give 9 as yellow prisms
which readily lost solvent molecules on standing in the air and changed to a beige-colored powder (cf. Footnote 5).
Data of 2b. Yellow crystals. M.p. 203 ± 2048 ([1]: 198 ± 1998). For all other spectral data, see [1] as well as
Tables 4 ± 6. Anal. calc. for C26H24O4S (432.54): C 72.20, H 5.59; found: C 72.19, H 5.85.
Data of 9: Yellow prisms. M.p. 2718 (dec.); Rf (CH2Cl2/MeOH 9 :1) 0.66. IR (KBr): 3240w, 3061w, 2922m,
2855m, 1703s, 1670m, 1625w, 1584m, 1548vs, 1447s, 1388m, 1307vs, 1266s, 1212s, 1144vs, 1085s, 1024m, 998w,
1
844m, 831w, 784m, 739s, 720s, 687s, 610m, 598s, 579s, 556s, 526s. H-NMR (300 MHz, CDCl3): 8.12 (d, Jo 7.4,
2 arom. H); 7.65 ± 7.45 (m, 8 arom. H); 6.50 (br. s, H C(4)); 5.84 (s, H C(10)); 5.72 (s, H C(8)); 4.21
(br. d, JAB 14.3, A of AB; PhSO2CH2); 3.69 (d, JAB 14.3, B of AB, PhSO2H2); 3.10 (dd, Jgem 25.4, Jvic 5.4,
1 H of CH2(5)); 2.73 (br. d, Jgem 25.5, 1 H of CH2(5)); 1.95 (br. s, Me C(7)); 1.84 (br. s, Me C(9)); 1.56
(s, Me C(11)); 1.30 (very br. s, Me C(6)). The broadened signals of atoms or groups at or around C(5)
indicate that a slow inversion of the boat conformation of ring B (see Fig. 1 as well as Sect. 4) takes place in soln.
at 308. 13C-NMR (75 MHz, CDCl3): 180.09 (C(1)O); 140.56 ± 125.70 (C(sp2); 17 signals of 20 are registered);
63.78 (PhSO2CH2); 55.69 (C(11b)); 24.46, 21.71, 19.93 (Me C(7,9,11)); 21.40 (br., Me C(6)). EI-MS: 574
.
(16, M ), 434(21), 433 (71, [M PhSO2] ), 432(24), 419 (22, [M PhSO2CH2] ), 418(17), 417(57),
.
.
405(16), 403(24), 292(18), 291 (60, [M 2 PhSO2] ), 277 (11, [M (PhSO2 PhSO2CH2)] ), 276(11),
.
275(11), 265(35), 263 (11, [M 2 PhSO2CH2] ), 261(12), 249(14), 207(18), 193(11), 189(10), 184(27),