D. Bastien et al. / Bioorg. Med. Chem. Lett. 20 (2010) 2078–2081
2081
(C–O); 1H NMR (200 MHz, CDCl3, d ppm) : 6.09 (2H, s, 6-CH and 7-CH), 5.65
(1H, s, 4-CH), 4.61 (1H, t, J = 7.8 Hz, 17-CH), 2.03 (3H, s, 17-OAc) 1.10 (3H, s, 19-
CH3), 0.86 (3H, s, 18-CH3).; 13C NMR (50 MHz, CDCl3, d ppm): 199.3 (C-3), 171.3
(17-OAc), 163.8 (C-5), 140.3 (C-7), 128.4 (C-4), 124.0 (C-6), 82.3 (C-17), 50.8,
48.3, 43.6, 37.6, 36.8, 36.7, 36.3, 34.1, 27.7, 23.3, 21.3, 20.4, 16.5, 12.2. MS (m/e)
328 (M+), 286 (M+- C2H2O), exact mass: calcd for C21H28O3: 328.2038; found:
328.2032.
for X-ray diffraction analysis and to Dr. Céline Van Themsche, Uni-
versité du Québec à Trois-Rivières, for her input in the preparation
of the Letter.
References and notes
Synthesis of
7a-allyl-4-androsten-17b-ol-3-one acetate (4): Under an inert
1. Jin, Y.; Penning, T. M.. Best Pract. Res. Clin. Endocrinol. Metab. 2001, 15, 79.
2. Heinlein, C. A.; Chang, C. Endocr. Rev. 2004, 25, 276.
3. Pereira de Jesus-Tran, K.; Cote, P. L. Protein Sci. 2006, 15, 987.
4. Portoghese, P. S. J. Med. Chem. 1992, 35, 1927.
atmosphere of nitrogen, the steroid 3 was dissolved in dry dichloromethane
and cooled to ꢀ78 °C. Then, titanium(IV) chloride (3.58 mL, 32.6 mmol) and
pyridine (0.65 mL, 6.39 mmol) were added to the solution. The mixture was
stirred for 5 min; allyltrimethylsilane was added, stirred for 1.5 h at ꢀ78 °C and
1.5 h at ꢀ30 °C. The black mixture was diluted with ether, washed with a 2%
HCl solution (2 ꢁ 20 mL) and with water (4 ꢁ 20 mL). The organic phase was
dried, filtered and concentrated to a solid. The crude steroid was purified by
flash chromatography with hexane/acetone (9:1) as the eluent. The crystalline
5. Bérubé, G. Curr. Med. Chem. 2006, 13, 131.
6. Millership, J. S.; Shanks, M. L. J. Pharm. Sci. 1988, 77, 116.
7. Bucourt, R.; Vignau, M.; Torelli, V.; Richard-Foy, H.; Geynet, C.; Secco-Millet, C.;
Redeuilh, G.; Baulieu, E.-E. J. Biol. Chem. 1978, 253, 8221.
8. Nickisch, K.; Laurent, H. Tetrahedron Lett. 1988, 29, 1533.
9. Yee, N. K.; Farina, V. J. Org. Chem. 2006, 71, 7133.
compound 4 was obtained in good yield (1.67 g, 70%). IR (NaCl, m
max, cmꢀ1):
1736 (C@O) 1678 (C@O), 1616 (C@C), 1243 (C–O); 1H NMR (200 MHz, CDCl3, d
ppm) : 5.70 (1H, s, 4-CH), 5.60 (1H, m, –CH@CH2), 5.00 (2H, m, –CH@CH2), 4.60
(1H, t, J = 8.4 Hz, 17-CH), 2.03 (3H, s, 17-OAc), 1.20 (3H, s, 19-CH3), 0.84 (3H, s,
18-CH3); 13C NMR (50 MHz, CDCl3, d ppm): 199.3 (C-3), 171.3 (17-OAc), 169.4
(C-5), 137.0 (C-21), 126.4 (C-4), 117.0 (C-22), 82.6 (C-17), 47.2, 46.2, 42.8, 38.9,
38.5, 36.7, 36.3, 36.2, 36.1, 34.2, 30.4, 27.6, 23.1, 21.4, 20.9, 18.2, 12.1. MS (m/e)
370 (M+), 312 (M+ꢀC2H2O2), exact mass: calcd for C24H34O3: 370.2508; found:
370.2505.
10. Cambridge Crystallographic Data Center (CCDC) deposit #765942. The
compound was recrystallized using
a mixture of dichloromethane and
diethyl ether. The presence of minute amount of chlorine atom in the final
resolution of the crystalline structure was observed and is believed to have
occurred during the recrystallization process.
11. Trnka, T. M.; Grubbs, R. H. Acc. Chem. Res. 2001, 34, 18.
12. Anhydrous reactions were performed under an inert atmosphere; the setup
was assembled and cooled under nitrogen. Unless otherwise noted, starting
material, reactant and solvents were obtained commercially and were used as
such or purified and dried by standard means.16 Organic solutions were dried
Synthesis of dimers of testosterone trans-T2 (5) and cis-T2 (6): Under nitrogen, the
steroid 4 (0.56 g, 1.51 mmol) was dissolved in dry dichloromethane (8 mL) and
Hoveyda–Grubbs 2nd generation (90 mg, 0.15 mmol) was added to that
solution. The mixture was stirred overnight at reflux and then 30 min at
room temperature. The solvent was evaporated. The product was purified by
flash chromatography (hexane/acetone, 95:5). That reaction gave two
separable isomeric dimers. The major product (trans-T2 (5), 0.26 g) was
obtained with 50% yield, while the minor product (cis-T2 (6), 0.13 g) was
obtained with 25% yield. Thin layer chromatography using hexane/acetone, 4:1
gave rf: 0.28 for cis-T2 (6) and rf: 0.24 for trans-T2 (5). The dimers were
hydrolysed, separately, using a 5 N HCl solution in methanol at reflux for 4.5 h.
The crude product was washed with a 5% NaHCO3 aqueous solution. The
organic phase was washed with water. The solvent was dried, filtered and
over magnesium sulfate (MgSO4), filtered and evaporated on
a rotary
evaporator under reduced pressure. All reactions were monitored by UV
fluorescence or staining 0with iodine. Commercial TLC plates were Sigma T 6145
(polyester silica gel 60 ÅA, 0,25 mm). Preparative TLC was performed on 1 mm
0
silica gel 60 ÅA, 20 ꢁ 20 plates (Whatman, 4861 840). Flash column
chromatography was performed according to the method of Still et al.17 on
Merck grade 60 Silica Gel, 230–400 mesh. All solvents used in chromatography
were distilled.
The infrared spectra were taken on
a
Nicolet Impact 420 FT-IR
spectrophotometer. Mass spectral assays for derivatives 2–4 were obtained
using a VG Micromass 7070 HS instrument using an ionization energy of 70 eV
concentrated to
purification was needed as the crude material was pure.
trans-T2 (5) (R = COCH3): mp: 123–126 °C; IR (NaCl,
max, cmꢀ1): 1734 (C@O),
a solid. The dimers were obtained with 95% yield; no
(Université de Sherbrooke). Derivatives
5 and 6 (R = H or CO2CH3) were
analyzed using a MS model 6210, Agilent technology instrument. The high
resolution mass spectra (HRMS) were obtained by TOF (time of flight) using ESI
(electrospray ionization) using the positive mode (ESI+) (Université du Québec
à Montréal). Nuclear magnetic resonance (NMR) spectra were recorded on a
m
1673 (C@O), 1611 (C@C), 1250 (C–O); 1H NMR (200 MHz, CDCl3, d ppm) : 5.63
(1H, s, 4-CH), 5.14 (1H, m, 21-CH), 4.59 (1H, t, J = 8.2 Hz, 17-CH), 2.03 (3H, s,
17-OAc), 1.19 (3H, s, 19-CH3), 0.83 (3H, s, 18-CH3); 13C NMR (50 MHz, CDCl3, d
ppm): 199.3 (C-3), 171.4 (17-OAc), 169.8 (C-5), 131.1 (C-21), 126.3 (C-4), 82.7
(C-17), 47.1, 46.2, 42.7, 38.9, 38.3, 36.6, 36.4, 36.1, 34.2, 31.2, 29.3, 27.6, 23.1,
21.4, 20.9, 18.2, 12.1. ESI+ HRMS: (M+H)+ calcd for C46H65O6: 713.4776; found:
713.4773 (M+H)+.
Varian
200 MHz
NMR
apparatus.
Samples
were
dissolved
in
deuterochloroform (CDCl3), or deuteroacetone (acetone-d6) for data
acquisition using tetramethylsilane or chloroform as internal standard (TMS,
d 0.0 ppm for 1H NMR and CDCl3 d 77.0 ppm for 13C). Chemical shifts (d) are
expressed in parts per million (ppm), the coupling constants (J) are expressed
in hertz (Hz). Multiplicities are described by the following abbreviations: s for
singlet, d for doublet, dd for doublet of doublets, t for triplet, q for quartet, m
for multiplet, #m for several multiplets and, br s for broad singlet.
trans-T2 (5) (R = OH): mp: 225–228 °C; IR (NaCl, m
max, cmꢀ1): 3422 (O–H), 1656
(C@O), 1217 (C–O); 1H NMR (200 MHz, CDCl3, d ppm) : 5.65 (1H, s, 4-CH), 5.17
(1H, m, 21-CH), 3.65 (1H, t, J = 5.1 Hz, 17-CH), 1.21 (3H, s, 19-CH3), 0.80 (3H, s,
18-CH3); 13C NMR (50 MHz, CDCl3, d ppm): 199.3 (C-3), 169.9 (C-5), 131.1 (C-
21), 126.3 (C-4), 81.9 (C-17), 47.3, 46.4, 43.1, 39.0, 38.6, 36.6, 36.4, 36.1, 34.2,
30.6, 29.9, 29.3, 23.0, 21.1, 18.2, 11.1. ESI+HRMS: (M+H)+ calcd for C42H61O4:
629.4564; found: 629.4563 (M+H)+.
Synthesis of 3,5-androstadien-3,17b-diol diacetate (2): Acetyl chloride (20.9 mL,
281.53 mmol), acetic anhydride (6.24 mL, 77.2 mmol) and pyridine (1.82 mL,
19.3 mmol) were added to testosterone (5.57 g, 19.3 mmol). The solution was
stirred 4 h at reflux and then 30 min at room temperature. The solvents were
evaporated to dryness under vacuum. The steroid was dissolved in
dichloromethane and filtered on silica gel. The solvent were evaporated to
obtain 6.46 g of the diacetate 2 (crude yield 90%). No flash chromatography
was needed for that step. The crude material showed a single spot on thin layer
chromatography and was used as such for the next transformation. IR (NaCl,
cis-T2 (6) (R = COCH3): mp: 241–244 °C; IR (NaCl, m
max, cmꢀ1): 1734 (C@O),
1673 (C@O), 1250 (C–O); 1H NMR (200 MHz, CDCl3, d ppm) : 5.61 (1H, s, 4-CH),
5.30 (1H, m, 21-CH), 4.65 (1H, t, J = 8.2 Hz, 17-CH), 2.03 (3H, s, 17-OAc), 1.17
(3H, s, 19-CH3), 0.83 (3H, s, 18-CH3); 13C NMR (50 MHz, CDCl3, d ppm): 198.9
(C-3), 171.3 (17-OAc), 169.8 (C-5), 129.8 (C-21), 126.6 (C-4), 82.8 (C-17), 47.0,
46.1, 42.7, 38.8, 38.5, 37.0, 36.4, 36.7, 36.1, 34.2, 27.7, 24.7, 23.2, 21.4, 21.0,
18.3, 12.1. ESI+HRMS: (M+H)+ calcd for C46H65O6: 713.4776; found: 713.4773
(M+H)+.
m
max, cmꢀ1): 1736 (C'O), 1666 (C'C), 1248 (C–O); 1H NMR (200 MHz, CDCl3, d
ppm) : 5.67 (1H, s, 4-CH), 5.36 (1H, m, 6-CH), 4.59 (1H, t, J = 8.2 Hz, 17-CH),
2.11 (3H, s, 3-OAc), 2.02 (3H, s, 17-OAc), 0.99 (3H, s, 19-CH3), 0.81 (3H, s, 18-
CH3)); 13C NMR (50 MHz, CDCl3, d ppm): 171.4 (17-OAc), 169.6 (3-OAc), 147.3
(C-3), 139.7 (C-5), 123.7 (C-6), 117.1 (C-4), 82.9 (C-17), 51.4, 48.1, 42.7, 36.9,
35.2, 33.9, 31.8, 31.6, 27.7, 25.0, 23.7, 21.4, 21.3, 20.9, 19.1, 12.3. MS (m/e): 372
(M+), 330 (M+ꢀC2H2O), exact mass: calcd for C23H32O4: 372.2300; found:
372.2297.
cis-T2 (6) (R = OH): mp: 127–130 °C; IR (NaCl, m
max, cmꢀ1): 3424 (O–H), 1658
(C@O), 1217 (C–O); 1H NMR (200 MHz, CDCl3, d ppm) : 5.60 (1H, s, 4-CH), 5.29
(1H, m, 21-CH), 3.78 (1H, t, J = 6.9 Hz, 17-CH), 1.18 (3H, s, 19-CH3), 0.79 (3H, s,
18-CH3); 13C NMR (50 MHz, CDCl3, d ppm): 199.0 (C-3), 170.5 (C-5), 129.9 (C-
21), 126.6 (C-4), 81.6 (C-17), 47.3, 46.3, 43.1, 38.84, 38.80, 36.9, 36.7, 36.2, 34.2,
30.4, 29.9, 24.9, 23.0, 21.1, 18.3, 11.2. ESI+HRMS: (M+H)+ calcd for C42H61O4:
629.4564; found: 629.4558 (M+H)+.
Synthesis of 4,6-androstadien-17b-ol-3-one acetate (3): Under
a nitrogen
atmosphere, DMF (70 mL) and water (3 mL) were combined with the
diacetate 2 (6.46 g, 17.3 mmol) and cooled to 0 °C. NBS was added over a
period of 1 h and stirred for an additional 40 min at 0 °C. Li2CO3 and LiBr were
added to the mixture at room temperature. The mixture was heated for 4 h at
95 °C and then was poured in a water/ice solution containing 150 mL of water
and 10 mL of acetic acid. The crude compound 3 was filtered and washed with
water and dried. Then, the crude material was purified by flash
chromatography with a mixture of hexane/acetone (9:1) to give 3 (4.33 g,
13. Carmichael, J.; DeGrapp, W. G.; Gazdar, A. F.; Minna, J. D.; Mitchell, J. B. Cancer
Res. 1987, 47, 936.
14. Ford, C. H. J.; Richardson, V. J.; Tsaltas, G. Cancer Chemother. Pharmacol. 1989,
24, 295.
15. Veldscholte, J.; Berrevoets, C. A. Biochemistry 1992, 31, 2393.
16. Perrin, D. D.; Armarego, W. L. F. Purification of Laboratory Chemicals, 3rd ed.;
Pergamon Press: Oxford, 1988.
17. Still, W. C.; Kahn, M. J. Org. Chem. 1978, 43, 2923.
76% yield). IR (NaCl, m
max, cmꢀ1): 1735 (C@O), 1664 (C@O), 1613 (C@C), 1252