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3.59 (m, 1 H); 3.42 (s, 3 H); 3.37 (s, 3 H); 1.97 (d, J ¼ 10.8, 1 H); 1.78 (s, 3 H); 1.12 (d, J ¼ 6, 3 H); 0.85 (s,
3 H); 0.75 (s, 3 H). 13C-NMR: 138.9; 134.1; 95.3; 94.4; 76.7; 71.2; 59.9; 56.0; 55.0; 53.3; 52.3; 43.8; 40.2;
39.5; 35.1; 34.5 (2 C); 31.4; 30.4; 28.0; 26.8; 25.7; 23.6; 19.6; 16.2; 12.0. Anal. calc. for C26H44O4 (420.63): C
74.24, H 10.54; found: C 74.22, H 10.78.
(1S,2S,5S)-2-[(1S,2S,4aS,6R,8aS)-1-Acetyldecahydro-6-(methoxymethoxy)-8a-methylnaphthalen-2-
yl]-5-[(1R)-1-(methoxymethoxy)ethyl]-1-methylcyclopentanecarboxaldehyde (11). A soln. of 10
(210 mg, 0.50 mmol) in CH2Cl2 (35 ml) was cooled to ꢀ788, and a slow stream of ozone was introduced
into the soln. until it became blue. Excess ozone was removed by flushing the soln. with O2. Me2S
(0.37 ml, 5 mmol) was then added, and the resulting mixture was stirred overnight from ꢀ788 to r.t. After
evaporation, the residue was directly purified by CC (SiO2, AcOEt/hexanes 1:4): 11 (113.2 mg, 50%).
Colorless oil. [a]D20 ¼ þ66.76 (c ¼ 1.745, CHCl3). IR: 3429, 2928, 1724, 1704, 1449, 1372, 1146, 1097, 1040,
917. 1H-NMR: 9.05 (s, 1 H); 4.65 (s, 2 H); 4.52 – 4.48 (m, 2 H); 3.82 (s, 1 H); 3.43 – 3.41 (m, 1 H); 3.37 (s,
3 H); 3.30 (s, 3 H); 2.37 (d, J ¼ 11.7, 1 H); 2.13 (s, 3 H); 1.11 (d, J ¼ 5.7, 3 H); 0.92 (s, 3 H); 0.84 (s, 3 H).
13C-NMR: 212.9; 204.8; 114.8; 94.5; 81.9; 71.2; 57.8; 56.8; 55.1; 54.9; 52.8; 51.2; 48.8; 48.3; 41.0; 36.5; 33.6;
32.1; 30.8; 27.9; 26.3; 25.0; 23.6; 22.2; 13.8; 12.4. Anal. calc. for C26H44O6 (452.62): C 68.99, H 9.80; found:
C 68.82, H 9.78.
(3a,5a,20R)-3,20-Bis(methoxymethoxy)-C-homopregn-12-en-11-one (¼(3aS,4S,6aS,6bS,8aS,10R,
12aS,12bS)-4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b-Tetradecahydro-10-(methoxymethoxy)-4-[(1R)-1-(meth-
oxymethoxy)ethyl]-3a,12a-dimethylnaphth[2,1-e]azulen-1(3aH)-one; 12). The mixture of 11 (45 mg,
0.1 mmol) and 1m KOH/MeOH (0.5 ml) in THF (10 ml) was stirred at r.t. for 24 h. After evaporation, the
residue was diluted with H2O (1 ml) and extracted with AcOEt (2 ꢁ 15 ml), the org. layer washed with
H2O and brine, and dried (Na2SO4), and evaporated, and the residue purified by CC (SiO2, AcOEt/
hexanes 1:3): 12 (27.4 mg, 63%). Oil. [a]2D0 ¼ þ26.33 (c ¼ 0.5005, CHCl3). IR: 3390, 2928, 1693, 1444,
1376, 1097, 1043, 918. 1H-NMR: 6.25 (d, J ¼ 12.3, 1 H); 5.82 (d, J ¼ 12.3, 1 H); 4.65 – 4.62 (m, 4 H); 3.82 (s,
1 H); 3.58 – 3.54 (m, 1 H); 3.43 (s, 3 H); 3.36 (s, 3 H); 2.29 (d, J ¼ 10.5, 1 H); 1.18 (d, J ¼ 5.7, 3 H); 0.95 (s,
3 H); 0.93 (s, 3 H). 13C-NMR: 213.5; 100.0; 94.4; 79.1; 75.3; 71.1; 71.0; 57.7; 56.8; 55.2; 51.4; 51.2; 47.9;
39.6; 37.4; 33.2; 33.0; 31.1; 30.7; 29.2; 26.2; 25.7; 24.8; 18.8; 12.5; 7.47. Anal. calc. for C26H42O5 (434.61): C
71.85, H 9.74; found: C 71.82, H 9.78.
(5a)-C-Homopregn-12-ene-3,11,20-trione (¼(3aS,4S,6aS,6bS,8aS,12aS,12bS)-4-Acetyl-3a,4,5,6,6a,
6b,7,8,8a,9,11,12,12a,12b-tetradecahydro-3a,12a-dimethylnaphth[2,1-e]azulene-1,10-dione; 13). The mix-
ture of 12 (44 mg, 0.10 mmol) and 3m HCl (0.5 ml) in THF (5 ml) was stirred at r.t. for 48 h. After
evaporation, the residue was diluted with AcOEt (15 ml), the soln. washed with 10% aq. NaHCO3 soln.,
H2O, and brine, dried (Na2SO4), and concentrated, and the residue dissolved in acetone (10 ml). To the
soln. was added Jones reagent at r.t. until appearance of an orange color, and then the reaction was
quenched by adding some i-PrOH. After evaporation, the residue was diluted with H2O (10 ml) and
extracted with CH2Cl2 (2 ꢁ 10 ml), the combined org. phase washed with H2O and brine, dried (Na2SO4),
and evaporated, and the residue purified by CC (SiO2, AcOEt/hexanes 1:2): 13 (31.5 mg, 92%). White
solid. M.p. 150 – 1528 (AcOEt/hexanes). [a]2D0 ¼ þ16.18 (c ¼ 0.7602, CHCl3). IR: 3390, 2928, 1710, 1693,
1444, 1376, 1097, 1043, 918. 1H-NMR: 6.34 (d, J ¼ 12.3, 1 H); 5.84 (d, J ¼ 12.3, 1 H); 2.63 (t, J ¼ 6.3, 1 H);
2.40 – 2.20 (m, 5 H); 2.15 (s, 3 H); 1.09 (s, 3 H); 0.94 (s, 3 H). 13C-NMR: 210.9; 208.6; 207.6; 144.8; 129.5;
69.9; 60.8; 52.3; 50.9; 46.1; 44.0; 37.9; 37.6 (2 C); 31.4; 31.3; 30.1; 29.3; 24.2; 22.7; 15.2; 12.6. Anal. calc. for
C22H30O3 (342.47): C 77.16, H 8.83; found: C 77.12, H 8.78.
(3a,5a)-3-Hydroxy-C-homopregn-12-ene-11,20-dione (¼(3aS,4S,6aS,6bS,8aS,10R,12aS,12bS)-4-
Acetyl-4,5,6,6a,6b,7,8,8a,9,10,11,12,12a,12b-tetradecahydro-10-hydroxy-3a,12a-dimethylnaphth[2,1-e]-
azulen-1(3aH)-one; 14). To a soln. of compound 13 (34.2 mg, 0.10 mmol) in dry THF (10 ml) was added
1m K-Selectride in THF (0.20 ml) at ꢀ 788, and the mixture was stirred at ꢀ 788 for 1 h. Then, the
reaction was quenched by adding H2O (1 ml). The mixture was extracted with AcOEt (2 ꢁ 10 ml), the
combined org. phase washed with H2O and brine, dried (Na2SO4), and concentrated and the residue
purified by CC (SiO2, AcOEt/hexanes 1:1.5): 14 (28 mg, 81%). White solid. M.p. 162 – 1648 (AcOEt/
hexanes). [a]2D0 ¼ þ12.42 (c ¼ 0.4350, CHCl3). IR: 3435, 2927, 1704, 1651, 1444, 1358, 1017, 730. 1H-NMR:
6.26 (d, J ¼ 12.3, 1 H); 5.79 (d, J ¼ 12.3, 1 H); 4.04 (s, 1 H); 2.70 (t, J ¼ 9.9, 1 H); 2.46 (d, J ¼ 12.6, 1 H);
2.14 (s, 3 H); 0.91 (s, 3 H); 0.87 (s, 3 H). 13C-NMR: 208.9; 208.2; 144.3; 129.9; 71.0; 66.2; 61.0; 52.7; 51.1;