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doi.org/10.1002/cmdc.202000966
ChemMedChem
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filtered and the filtrate was dissolved in MeOH (100 mL), followed
by the addition of pyridine (1.8 mL) and methoxyamine
hydrochloride (1.85 g). The reaction was heated to 55°C under
reflux for 8–10 h, monitored by TLC. The crude product was purified
by silica gel column chromatography with petroleum ether/ethyl
acetate (20:1) to obtain the desired product 4 (2.4 g, 76%) as a
20S isomer 9: 0.86 g, 43%). 20R isomer 8: [α] =À 62.0° (c=1.0,
D
1
MeOH), H NMR (600 MHz, CDCl ): δ=5.34 (s, 1H), 3.56–3.47 (m, 4H),
3.01–2.93 (m, 1H), 2.37–2.13 (m, 2H), 2.09–1.88 (m, 2H), 1.87–1.70
(m, 3H), 1.23–1.17 (m, 1H), 1.08 (s, 3H), 1.00 (s, 3H), 0.74 (s, 3H). C
NMR (150 MHz, CDCl ): δ=140.9, 121.7, 71.9, 62.3, 58.6, 56.5, 53.3,
50.1, 42.4, 42.1, 39.8, 37.4, 36.6, 31.9, 31.9, 31.7, 26.7 24.4, 21.1, 19.5,
18.6, 12.3. HRMS (ESI-MS) m/z calcd. for C H NO : 348.2897 [M+
3
1
3
3
1
mixture of (26E) and (26Z) stereoisomers. H NMR (500 MHz, C D N):
5
5
22 38
2
+
20
D
δ=5.36 (d, J=5.2 Hz, 1H), 4.84–4.76 (m, 1H), 4.37–4.33 (m, 1H),
H] ; found: 348.2879. 20S isomer 9: [α] =À 30.6° (c=1.0, MeOH),
1
3
5
1
3
1
.94–3.86 (m, 3H), 3.41–3.31 (m, 1H), 1.05 (d, J=6.9 Hz, 3H), 0.98 (s,
H NMR (600 MHz, CDCl ): δ=5.35–5.33 (m, 1H), 3.53 (s, 3H), 3.52–
3
13
H), 0.86 (s, 3H). C NMR (125 MHz, C D N): δ=170.6, 155.4, 140.3,
3.48 (m, 1H), 2.86–2.79 (m, 1H), 2.31–2.19 (m, 2H), 2.00–1.93 (m, 2H),
5
5
1
3
23.0, 90.4, 83.7, 74.4, 65.8, 61.5, 57.3, 50.6, 41.2, 39.8, 38.8, 38.6,
7.6, 37.3, 35.2, 33.0, 32.6, 32.5, 32.1, 31.8, 28.4, 21.6, 21.3, 19.7, 19.4,
8.6, 16.9. HRMS (ESI-MS) m/z calcd. for C H NO : 486.3578 [M+
1.88–1.80 (m, 3H), 1.19 (d, J=6.2 Hz, 3H), 1.00 (s, 3H), 0.69 (s, 3H). C
NMR (150 MHz, CDCl ): δ=140.9, 121.7, 71.9, 62.7, 59.7, 56.5, 53.0,
50.1, 42.4, 42.2, 39.3, 37.4, 36.6, 31.9, 31.9, 31.7, 26.9, 24.4, 21.1, 19.5,
18.6, 12.3. HRMS (ESI-MS) m/z calcd. for C H NO : 348.2897 [M+
3
30
48
4
+
H] ; found: 486.3578.
2
2
38
2
+
H] ; found: 348.2896.
Synthesis of (25R)-3β-hydroxy-26-N-methoxyamino-furost-5-en
(
5). Compound 4 (1.9 g, 4 mmol) was dissolved in a mixture of THF/
Synthesis of 17-N-methoxyiminodehydroepiandrosterone (11).
Compound 10 (2.8 g, 10 mmol) was dissolved in a mixture of
MeOH/CH Cl (4:1, 100 mL), followed by the addition of pyridine
(5 equiv.) and methoxyamine hydrochloride (1.12 g, 13.5 mmol).
The reaction mixture was stirred at room temperature for 8 h and
monitored by TLC, and then filtered to obtain an organic layer and
was concentrated under reduced pressure, the crude product was
purified by silica gel column chromatography with petroleum
MeOH (1:1,200 mL), KOH (3.2 g, 5.7 mmol) was added, the reaction
mixture was stirred at room temperature for 10–12 h, and
monitored by TLC. The solvent was concentrated under reduced
pressure. The residue was purified by column chromatography
2
2
(petroleum ether/ethyl acetate 15:1) to give as a white solid
(1.45 g). The solid was dissolved in AcOH (100 mL) and NaCNBH3
(2 g, 3 mmol) was added, then the reaction mixture was stirred at
room temperature for 12 h. After quenching the reaction with
saturated NaHCO3 solution, and then extracted with CH Cl (3×
ether/ethyl acetate (20:1), obtained the desired product as a white
1
solid (2.9 g, 91%). H NMR (500 MHz, CDCl ): δ=5.37–5.34 (m, 1H),
2
2
3
1
3
100 mL). The organic layer was washed with saturated NaCl solution
3.82 (s, 3H), 3.58–3.46 (m, 1H), 1.03 (s, 3H), 0.92 (s, 3H). C NMR
(
3×50 mL), dried over anhydrous Na SO4 and concentrated. The
(125 MHz, CDCl ): δ=170.5, 141.2, 121.3, 71.8, 61.4, 54.4, 50.5, 43.9,
2
3
crude reaction mixture was purified by silica gel column chroma-
tography with petroleum ether/ethyl acetate (10:1) to obtain white
powder compound 5 (1.1 g, 76%). H NMR (500 MHz, C D N): δ=
42.4, 37.4, 36.8, 34.3, 31.8, 31.5, 31.5, 25.8, 23.5, 20.7, 19.6, 17.2.
+
HRMS (ESI-MS) m/z calcd. for C H NO : 318.2428 [M+H] ; found:
2
0
32
2
1
318.2429.
5
5
5
3
2
.41 (d, J=5.1 Hz, 1H), 4.40–4.33 (m, 1H), 3.93–3.79 (m, 1H), 3.63 (s,
H), 3.44–3.40 (m, 1H), 3.07–2.99 (m, 1H), 2.83 (d, J=7.4 Hz, 1H),
.69–2.54 (m, 2H), 2.17–1.98 (m, 2H), 1.97–1.38 (m, 16H), 1.35–1.24
Synthesis of (17S)-N-Methoxyaminodehydroepiandrosterone (12).
Compound 11 (2 g, 6.3 mmol) was dissolved in AcOH (100 mL),
which was subsequently reduced by NaCNBH3 (10 equiv.), the
reaction mixture was stirred at room temperature for 10 h. The
reaction was terminated by adding saturated NaHCO3 solution
(
m, 2H), 1.19–1.06 (m, 3H), 1.05 (s, 3H), 1.02 (d, J=4.5 Hz, 3H), 1.01
13
(d, J=4.5 Hz, 3H), 0.91 (s, 3H). C NMR (125 MHz, C D N): δ=142.3,
5 5
121.4, 90.7, 83.7, 71.6, 65.9, 61.8, 58.9, 57.5, 50.9, 43.9, 41.2, 40.0,
38.6, 38.2, 37.4, 33.0, 33.0, 32.9, 32.7, 32.3, 31.9, 31.7, 21.4, 20.0, 19.4,
18.7, 17.0. HRMS (ESI-MS) m/z calcd. for C H NO : 446.3629 [M+
(
100 mL), and then extracted with CH Cl (3×100 mL). The organic
2 2
layer was washed with saturated NaHCO solution, and dried over
3
28
48
3
+
anhydrous MgSO . Filtration and removal of the solvent, the residue
4
H] ; found: 446.3635.
was purified by silica gel chromatography with petroleum ether/
Synthesis of 20-N-methoxyiminopregnenolone (7). Compound 6
ethyl acetate (20:1), obtained the desired product as a white solid
1
(
5 g, 15.8 mmol) was dissolved in a mixture of MeOH/CH Cl (4:1,
(1.8 g, 90%). H NMR (500 MHz, CDCl ): δ=5.34 (d, J=5.2 Hz, 1H),
2
2
3
2
00 mL) followed by the addition of pyridine (5 equiv.) and meth-
3.64–3.39 (m, 4H), 3.04 (t, J=8.8 Hz, 1H), 2.36–2.16 (m, 2H), 2.05–
oxyamine hydrochloride (2.02 g, 24.2 mmol). The reaction mixture
was stirred at room temperature for 10 h, and monitored by TLC,
and then filtered to obtain an organic layer and was concentrated
under reduced pressure, the crude product was purified through
silica gel column chromatography with petroleum ether/ethyl
1.74 (m, 5H), 1.69–1.16 (m, 10H), 1.11–1.04 (m, 2H), 1.01 (s, 3H),
1
3
0.99–0.91 (m, 1H), 0.75 (s, 3H). C NMR (125 MHz, CDCl ): δ=141.0,
3
121.5, 71.9, 70.2, 61.6, 53.9, 50.4, 42.7, 42.4, 38.5, 37.4, 36.7, 31.9,
31.8, 31.8, 26.1, 24.0, 21.0, 19.6, 11.8. HRMS (ESI-MS) m/z calcd. for
+
C H NO : 320.2584 [M+H] ; found: 320.2588.
2
0
34
2
acetate (20:1), obtained the desired product as a white solid 7
1
Synthesis of 17-N-Methoxyiminoestrone (14). Compound 13
2.7 g, 10 mmol) was dissolved in a mixture of MeOH/CH Cl (1:1,
(
4.9 g, 90%). H NMR (600 MHz, CDCl ): δ=5.35 (d, J=3.8 Hz, 1H),
3
(
2
2
3
.84 (s, 3H), 3.56–3.49 (m, 1H), 1.81 (s, 3H), 1.00 (s, 3H), 0.64 (s, 3H).
1
3
80 mL), followed by the addition of pyridine (5 equiv.) and meth-
oxyamine hydrochloride (1.09 g, 13 mmol). The reaction mixture
was stirred at room temperature for 8 h and monitored by TLC. The
reaction mixture was filtered to obtain an organic layer and was
concentrated under reduced pressure, the crude product was
purified by silica gel column chromatography with petroleum
ether/ethyl acetate (20:1), obtained the desired product as a white
C NMR (150 MHz, CDCl ): δ=157.9, 140.9, 121.7, 71.9, 61.4, 56.7,
3
5
6.4, 50.3, 43.8, 42.4, 38.8, 37.4, 36.7, 32.2, 31.9, 31.8, 24.4, 23.2, 21.2,
1
9.6, 15.7, 13.3. HRMS (ESI-MS) m/z calcd. for C H NO : 346.2741
M+H] ; found: 346.2726.
22
36
2
+
[
Synthesis of (20R)-N-methoxyaminopregnenolone (8) and (20S)-
N-methoxyaminopregnenolone (9). Compound 7 (2 g, 5.8 mmol)
was dissolved in AcOH (100 mL), which was subsequently reduced
1
solid (2.8 g, 95%). H NMR (500 MHz, C D N): δ=7.28 (d, J=8.4 Hz,
5
5
by NaCNBH (10 equiv.), the reaction mixture was stirred at room
1H), 7.11 (dd, J=8.4, 2.6 Hz, 1H), 7.02 (d, J=2.5 Hz, 1H), 3.95 (s, 3H),
0.93 (s, 3H). C NMR (125 MHz, C D N): δ=170.2, 157.2, 138.5, 131.5,
5 5
127.3, 116.7, 114.3, 61.6, 53.5, 44.8, 44.8, 39.0, 35.3, 30.3, 28.0, 27.1,
3
13
temperature for 10 h. The reaction was terminated by adding
saturated NaHCO3 solution (100 mL), and then extracted with
CH Cl (3×100 mL). The organic layer was washed with saturated
26.4, 23.5, 17.9. HRMS (ESI-MS) m/z calcd. for C H NO : 300.1958
2
2
19 26
2
+
NaHCO solution, and dried over anhydrous MgSO . Filtration and
[M+H] ; found: 300.1938.
3
4
removal of the solvent, the crude product was purified by silica gel
chromatography with petroleum ether/ethyl acetate (30:1) provid-
ing the two aglycons as white powder (20R isomer 8: 0.94 g, 47%;
Synthesis of (17S)-N-methoxyaminoestrone (15). Compound 14
1.5 g, 5 mmol) was dissolved in AcOH (100 mL), the mixture was
(
ChemMedChem 2021, 16, 1488–1498
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