1810 J ournal of Medicinal Chemistry, 2001, Vol. 44, No. 11
Labaree et al.
(d, 1H, J ) 8.4 Hz, H-1); HRMS (ES) calcd for C21H32NO4 (M
+ NH4+) m/e 362.2331, found m/e 362.2331. Anal. (C21H28O4)
C, H.
heating to dissolve, evaporation of the solvent, and resuspen-
sion in 1 mL of vinyl propionate. The reaction mixture was
stirred at 92 °C for 4 h, poured into CH2Cl2 (50 mL), and
washed with saturated aqueous NaHCO3 (20 mL) and H2O
(20 mL). The organic layer was dried over Na2SO4 and
concentrated in vacuo. Purification of the residue by flash
chromatography on a 2 × 17 cm column of silica gel using
hexanes/EtOAc (3:1) gave 20 mg (76%) of 15 as a white solid.
Purification of 7 mg of this material in HPLC system H-7,
followed by crystallization from Et2O/hexane, gave 5 mg of 15
for bioassay. Data for 15: TLC, T-6, Rf 0.57; 1H NMR (500
MHz, CDCl3) δ 0.86 (s, 3H, H-18), 3.95 (d, 1H, J ) 7.7 Hz,
H-17R), 4.63 (dd, 1H, J ) 6.3, 1.6 Hz, vinyl-H), 4.94 (dd, 1H,
J ) 14.0, 1.6 Hz, vinyl-H), 6.57 (d, 1H, J ) 2.8 Hz, H-4), 6.64
(dd, 1H, J ) 8.3, 2.8 Hz, H-2), 7.16 (d, 1H, J ) 8.3 Hz, H-1),
7.33 (dd, 1H, J ) 14.0, 6.3 Hz, vinyl-H); HRMS (ES) calcd for
P r op yl (3,17â-Dih yd r oxyestr a -1,3,5(10)-tr ien -16r-yl)-
for m a te (11, E16-1,3). Compound 11 was prepared by esteri-
fication of acid 8 (66 mg, 0.209 mmol) with n-propanol as
described for the preparation of 9. Purification of the residue
by flash chromatography on a 2 × 15 cm column of silica gel
using hexanes/EtOAc (2:1) as eluent gave 46 mg (62%) of 11
as a white solid. Purification of 22 mg of this material by HPLC
(H-5) gave 20 mg of 11 for bioassay. Data for 11: TLC, T-2, Rf
1
) 0.41; H NMR (500 MHz, CDCl3) δ 0.85 (s, 3H, H-18), 0.98
(t, 3H, J ) 7.6 Hz, CH3), 3.88 (d, 1H, J ) 7.4 Hz, H-17R), 4.11
(m, 2H, OCH2), 6.57 (d, 1H, J ) 2.5 Hz, H-4), 6.63 (dd, 1H, J
) 8.3, 2.5 Hz, H-2), 7.16 (d, 1H, J ) 8.3 Hz, H-1); HRMS (ES)
calcd for C22H34NO4 (M + NH4+) m/e 376.3488, found m/e
376.2493; HPLC system, H-3, 280 nm, tR ) 12 min, and system
H-5, 280 nm, tR ) 9.5 min, >99% pure.
C
21H30NO4 (M + NH4+) m/e 360.2175, found m/e 360.2171;
HPLC system H-3, 280 nm, tR ) 12.21 min, and system H-8,
280 nm, tR ) 11.5 min, >99% pure.
Isop r op yl (3,17â-Dih yd r oxyest r a -1,3,5(10)-t r ien -16r-
yl)for m a te (12, E16-1,3i). A solution of 44 mg (0.14 mmol)
of acid 8 and 10 mg (0.053 mmol) of pTsOH in 2-propanol (20
mL) was stirred and heated at 85 °C for 18 h. A Dean-Stark
trap filled with 4 Å sieves was added and heating was
continued for 18 h. the reaction mixture was allowed to cool
to room temperature, poured into saturated aqueous NaHCO3
(20 mL), and extracted with CH2Cl2 (3×, 50 mL). The combined
organic extracts were dried over Na2SO4 and concentrated in
vacuo. Purification of the residue by flash chromatography on
a 2 × 15 cm column of silica gel using hexanes/EtOAc (2:1) as
eluent gave 21 mg (43%) of 12 as a white solid. Purification of
this material by HPLC in system H-3, 280 nm, followed by
crystallization from acetone/petroleum ether, gave 8 mg of 12
for bioassay. Data for 12: TLC, T-6, Rf 0.55; 1H NMR (500
MHz, CDCl3) δ 0.84 (s, 3H, H-18), 1.28 (d, 3H, J ) 6.5 Hz,
CH3), 1.282 (d, 3H, J ) 6.5 Hz, CH3), 3.85 (br d, 1H, J ) 9.3
Hz, H-17R), 5.07 (sept, 1H, J ) 6.5 Hz, -CH-), 6.57 (d, 1H, J
) 2.7 Hz, H-4), 6.63 (dd, 1H, J ) 8.3, 2.7 Hz, H-2), 7.15 (d,
1H, J ) 8.3 Hz, H-1); HRMS (ES) calcd for C22H34NO4 (M +
NH4+) m/e 376.2488, found m/e 376.2485; HPLC system, H-3,
280 nm, tR ) 11 min, and system H-6, 280 nm, tR ) 7 min,
>99% pure.
n -Bu tyl (3,17â-Dih yd r oxyestr a -1,3,5(10)-tr ien -16r-yl)-
for m a te (13, E16-1,4). Compound 13 was prepared by esteri-
fication of acid 8 (59 mg, 0.19 mmol) with butanol as described
for the preparation of 9. Purification of the residue by flash
chromatography on a 2 × 15 cm column of silica gel gave 50
mg (73%) of 13 as a white solid. Data for 13: TLC, T-2, Rf
0.30; 1H NMR (500 MHz, CDCl3) δ 0.85 (s, 3H, H-18), 0.96 (t,
3H, J ) 7.4 Hz, -CH3), 3.87 (d, 1H, J ) 8.0 Hz, H-17R), 4.15
(m, 2H, OCH2), 6.57 (d, 1H, J ) 2.7 Hz, H-4), 6.63 (dd, 1H, J
) 8.4, 2.7 Hz, H-2), 7.15 (d, 1H, J ) 8.4 Hz, H-1); HRMS (ES)
calcd for C23H36NO4 (M + NH4+) m/e 390.2644, found m/e
390.2647. HPLC system H-3, 280 nm, tR ) 11 min, and system
H-6, 280 nm, tR ) 9 min, >99% pure.
2′-F lu or oeth yl (3,17â-Dih yd r oxyestr a -1,3,5(10)-tr ien -
16r-yl)for m a te (16, E16-1,2 F 1). Compound 16 was prepared
by esterification of acid 8 (16 mg, 0.05 mmol) with 1.5 mL of
fluoroethanol in 1.5 mL of toluene as described for the
preparation of 12. Purification of the residue by flash chro-
matography on a 2 × 16 cm column of silica gel using hexanes/
EtOAc (2:1) as eluent gave 11 mg (59%) of 16 as a white solid.
Purification of this material by HPLC in system H-3, followed
by crystallization from Et2O/petroleum ether, gave 8 mg of 16
for bioassay. Data for 16: TLC, T-6, Rf ) 0.375; 1H NMR (500
MHz, CDCl3) δ 0.85 (s, 3H, H-18), 3.91 (d, 1H, J ) 8.2 Hz,
H-17R), 4.36-4.44 (m 2H, CH2CH2F), 4.64 (dt, 2H, J ) 47.4,
4.2 Hz, CH2CH2F), 6.57 (d, 1H, J ) 2.8 Hz, H-4), 6.63 (dd, 1H,
J ) 8.3, 2.8 Hz, H-2), 7.16 (d, 1H, J ) 8.3, H-1); HRMS (ES)
calcd for C21H31FNO4 (M + NH4+) m/e 380.2237, found m/e
380.2248; HPLC, system H-3, 280 nm, tR ) 13.0 min, and
system H-8, 280 nm, tR ) 8.5 min, >99% pure.
2′,2′-Diflu or oeth yl (3,17â-Dih ydr oxyestr a-1,3,5(10)-tr ien -
16r-yl)for m a te (17, E16-1,2 F 2). Compound 17 was prepared
by esterification of acid 8 (25 mg, 0.08 mmol) with 2,2-
difluoroethanol as described for the preparation of 16. Puri-
fication of this residue by flash chromatography on a 2 × 17
cm column of silica gel using hexanes/EtOAc (3:1) followed by
hexanes/EtOAc (2:1) as eluent gave 29 mg of 17 as a yellow
oil. Purification of this material by HPLC with system H-3
gave 23 mg (74%) of 17 as a clear colorless oil. Further HPLC
purification of 6 mg of this material with system H-7, followed
by crystallization from Et2O/hexanes, gave 5 mg of 17 for
1
bioassay. Data for 17: TLC, T-6, Rf 0.5; H NMR (500 MHz,
CDCl3) δ 0.85 (s, 3H, H-18), 3.91 (d, 1H, J ) 8.3 Hz, H-17R),
4.32-4.39 (m, 2H, CH2CHF2), 5.99 (tt, 1H, J ) 55.2, 4.0 Hz,
CH2CHF2), 6.57 (d, 1H, J ) 2.8 Hz, H-4), 6.64 (dd, 1H, J )
8.4, 2.8 Hz, H-2), 7.16 (d, 1H, J ) 8.4 Hz, H-1); HRMS (ES)
calcd for C21H30F2NO4 (M + NH4+) m/e 398.2143, found m/e
398.2148; HPLC system H-3, 280 nm, tR ) 12.8 min, and
system H-8, 280 nm, tR ) 10.5 min, >99% pure.
2,2-Dim et h ylp r op yl (3,17â-Dih yd r oxyest r a -1,3,5(10)-
tr ien -16r-yl)for m a te (14, E16-1,5n eo). Compound 14 was
prepared by esterification of acid 8 (85 mg, 0.27 mmol) with 2
mL of neopentyl alcohol in 10 mL of benzene as described for
the preparation of 12. Purification of the residue by flash
chromatography on a 2 × 16 cm column of silica gel using
hexanes/EtOAc (3:1) gave 92 mg (89%) of 14 as a white solid.
2′,2′,2′-Tr iflu or oeth yl (3,17â-Dih yd r oxyestr a -1,3,5(10)-
tr ien -16r-yl)for m a te (18, E16-1,2 F 3). Compound 18 was
prepared by esterification of acid 8 (25 mg, 0.079 mmol) with
2,2,2-trifluoroethanol as described for the preparation of 16.
Purification of the residue by flash chromatography on a 2 ×
17 cm column of silica gel using hexanes/EtOAc (4:1) as eluent
gave 19 mg of 18. HPLC purification of this material with
system H-3 gave 17 mg (54%) of 18 as a slightly yellow oil.
Further HPLC purification of 3 mg of this material with
system H-8, followed by crystallization from Et2O/hexanes,
gave 2 mg of 18 as an amorphous solid. Data for 18: TLC,
1
Data for 14: TLC, T-5, Rf 0.77; H NMR (500 MHz, CDCl3) δ
0.86 (s, 3H, H-18), 0.97 (s, 9H, CH3), 3.83 & 3.87 (AB quartet,
2H, J ) 10.5 Hz, -CH2-), 3.90 (d, 1H, J ) 8.1 Hz, H-17R),
6.57 (d, 1H, J ) 2.6 Hz, H-4), 6.63 (dd, 1H, J ) 8.5, 2.6 Hz,
H-2), 7.15 (d, 1H, J ) 8.5 Hz, H-1); HRMS (ES) calcd for
C
24H38NO4 (M + NH4+) m/e 404.2801, found m/e 404.2809.
1
Anal. (C24H34O4) C, H.
T-6, Rf 0.58; H NMR (500 MHz, CDCl3) δ 0.86 (s, 3H, H-18),
3.92 (d, 1H, J ) 8.3 Hz, H-17R), 4.52-4.58 (m, 2H, CH2CF3),
6.57 (d, 1H, J ) 3.0 Hz, H-4), 6.64 (dd, 1H, J ) 8.4, 3.0 Hz,
H-2), 7.15 (d, 1H, J ) 8.4 Hz, H-1); HRMS (ES) calcd for
Vin yl (3,17â-Dih yd r oxyestr a n -1,3,5(10)-tr ien -16r-yl)-
for m a te (15, E16-1,2 vin ). A solution of 24 mg (0.077 mmol)
of acid 8 in 2 mL of vinyl propionate was stirred as 20 µL of a
0.1 M solution of PdCl2-LiCl in vinyl propionate was added.
This solution was prepared by combining 17 mg (0.1 mmol) of
PdCl2 and 4.2 mg (0.1 mmol) of LiCl in 1 mL of MeOH with
C
21H29F3NO4 (M + NH4+) m/e 416.2049, found m/e 416.2051;
HPLC system H-3, 280 nm, tR ) 11.6 min, and system H-8,
280 nm, tR ) 13.5 min, >99% pure.