4906
K. Sasaki et al. / Bioorg. Med. Chem. 13 (2005) 4900–4911
to afford 22b-methoxy-3b,24-isopropylidenedioxyolean-
12-ene (173 mg, 85%) as a white solid.
mixture was refluxed for an additional 22 h. The mixture
was cooled to 0 ꢁC, carefully diluted with ice water
(5 ml), and extracted with EtOAc (50 ml). The organic
layer was washed with water, dried over MgSO4, fil-
tered, and concentrated in vacuo. The residue was puri-
fied by flash chromatography on silica gel (n-hexane/
EtOAc, 10:1) to afford the 22a-ol 11 (378 mg, 75%)
and 22b-ol 3 (31 mg, 6%).
22b-Methoxy-3b,24-isopropylidenedioxyolean-12-ene was
subjected to the deprotection reaction using the same
procedure as for 4, to give 7 (140 mg, 88%) as a white
+81.4
23
D
solid. Compound 7: mp 238–239 ꢁC; ½aꢁ
1
(c 1.01, CHCl3); H NMR (CDCl3) d 0.85 (3H, s), 0.89
(3H, s), 0.90 (3H, s), 0.94 (3H, s), 1.00 (3H, s), 1.11 (3H,
s), 1.25 (3H, s), 0.83–2.11 (21H, m), 2.38 (1H, d,
J = 4.2 Hz), 2.70 (1H, dd, J = 2.5 and 8.9 Hz), 2.81 (1H,
dd, J = 2.8 and 6.7 Hz), 3.28 (3H, s), 3.36 (1H, t,
J = 11.0 Hz), 3.41–3.48 (1H, m), 4.22 (1H, dd, J = 2.6
and 11.0 Hz), 5.22 (1H, t, J = 3.6 Hz); Anal. Calcd for
C31H52O3: C, 78.76; H 11.09. Found: C, 78.54; H, 11.11.
Compound 11 was submitted to the deprotection reac-
tion using the same procedure as for 4, to give 12
(190 mg, 98%) as a white solid: 12. mp 243–245 ꢁC;
23
D
1
½aꢁ +75.1 (c 0.92, CHCl3); H NMR (CDCl3) d 0.89
(3H, s), 0.92 (3H, s), 0.93 (3H, s), 0.94 (3H, s), 0.98
(3H, s), 1.15 (3H, s), 1.25 (3H, s), 0.83–2.02 (22H, m),
2.47 (1H, d, J = 4.4 Hz), 2.74 (1H, dd, J = 2.6 and
8.7 Hz), 3.32–3.38 (1H, m), 3.42–3.47 (1H, m), 3.51–
3.57 (1H, m), 4.21 (1H, dd, J = 2.6 and 11.3 Hz), 5.20
(1H, t, J = 3.6 Hz); HRMS (FAB) Calcd for
C30H50O3Na [M+Na]+ 481.3658. Found 481.3654.
5.1.6. 22b-Ethoxylolean-12-ene-3b,24-diol (8). Com-
pound 8 was prepared through the procedure as de-
scribed for 7, except for using ethyl iodide in place of
methyl iodide, in 67% yield from 3. Compound 8: mp
23
D
231–233 ꢁC; ½aꢁ +84.0 (c 1.00, CHCl3); 1H NMR
(CDCl3) d 0.86 (3H, s), 0.89 (3H, s), 0.90 (3H, s), 0.95
(3H, s), 1.01 (3H, s), 1.12 (3H, s), 1.14 (3H, t,
J = 7.2 Hz), 1.25 (3H, s), 0.84–2.13 (21H, m), 2.40
(1H, d, J = 4.2 Hz), 2.70 (1H, d, J = 8.8 Hz), 2.89 (1H,
dd, J = 2.8 and 6.4 Hz), 3.22–3.30 (1H, m), 3.35 (1H,
t, J = 9.7 Hz), 3.42–3.47 (1H, m), 3.52–3.60 (1H, m),
4.21 (1H, d, J = 9.7 Hz), 5.21 (1H, t, J = 3.6 Hz); Anal.
Calcd for C32H54O3: C, 78.96; H 11.18. Found: C,
78.84; H, 11.10.
5.1.9. 22a-Acetoxyolean-12-ene-3b,24-diol (13). Com-
pound 13 was prepared through the procedure for 4
from 3 in 89% yield from 11. Compound 13: mp 215–
23
1
216 ꢁC; ½aꢁ +70.2 (c 1.02, CHCl3); H NMR (CDCl3)
D
d 0.87 (3H, s), 0.89 (3H, s), 0.91 (3H, s), 0.93 (3H, s),
0.99 (3H, s), 1.16 (3H, s), 1.25 (3H, s), 2.02 (3H, s),
0.82–2.08 (21H, m), 2.55 (1H, br s), 2.81 (1H, br s),
3.35 (1H, t, J = 11.0 Hz), 3.43–3.48 (1H, m), 4.20 (1H,
d, J = 11.0 Hz), 4.81 (1H, dd, J = 5.9 and 11.3 Hz),
5.22 (1H, t, J = 3.6 Hz); Anal. Calcd for C32H52O4Æ2/
5H2O: C, 75.66; H, 10.48. Found: C, 75.74; H, 10.49.
5.1.7. 22b-Allyloxylolean-12-ene-3b,24-diol (9). Com-
pound 9 was prepared as described for 7, except for
using allyl iodide in place of methyl iodide, in 57% yield
5.1.10. 22a-Methoxyolean-12-ene-3b,24-diol (14). Com-
pound 14 was prepared as described for 7 from 3 in
69% yield from 11. Compound 14: mp 214–215 ꢁC;
23
from 3. Compound 9: mp 210–211 ꢁC; ½aꢁ +76.9 (c
D
1
1.00, CHCl3); H NMR (CDCl3) d 0.88 (3H, s), 0.89
(3H, s), 0.90 (3H, s), 0.94 (3H, s), 1.01 (3H, s), 1.11
(3H, s), 1.25 (3H, s), 0.84–2.15 (21H, m), 2.41 (1H, br
s), 2.71 (1H, br s), 2.97 (1H, dd, J = 2.8 and 6.4 Hz),
3.34 (1H, d, J = 11.0 Hz), 3.42–3.48 (1H, m), 3.79 (1H,
tdd, J = 1.5, 5.4, and 13.1 Hz), 4.05 (1H, tdd, J = 1.5,
5.4 and 13.1 Hz), 4.20 (1H, d, J = 11.0 Hz), 5.11 (1H,
dd, J = 2.1 and 10.5 Hz), 5.21–5.28 (2H, m), 5.84–5.95
(1H, m); Anal. Calcd for C33H54O3: C, 79.46; H 10.91.
Found: C, 79.24; H, 10.64.
23
D
1
½aꢁ +83.1 (c 0.96, CHCl3); H NMR (CDCl3) d 0.89
(3H, s), 0.92 (3H, s), 0.93 (3H, s), 0.94 (3H, s), 0.96
(3H, s), 1.14 (3H, s), 1.25 (3H, s), 0.83–1.99 (21H, m),
2.49 (1H, br s), 2.76 (1H, d, J = 7.2 Hz), 2.96 (1H, dd,
J = 4.5 and 12.2 Hz), 3.33 (3H, s), 3.33–3.37 (1H, m),
3.42–3.47 (1H, m), 4.20 (1H, d, J = 11.3 Hz), 5.19 (1H,
t, J = 3.6 Hz); Anal. Calcd for C31H52O3Æ1/2H2O: C,
77.29; H, 11.09. Found: C, 77.42; H, 11.08.
5.1.11. Soyasapogenol C (16). A solution of 3 (500 mg,
1.0 mmol) in pyridine (5 ml) was treated with p-toluene-
sulfonyl chloride (287 mg, 1.5 mmol) and a small
amount of 4-DMAP at room temperature. After stirring
overnight, the mixture was cooled to 0 ꢁC, diluted with
water, and extracted with EtOAc. The organic layer
was washed with water, dried over MgSO4, filtered,
and concentrated in vacuo to furnish the desired inter-
mediary tosylate as an oil (654 mg, 100%).
5.1.8. Olean-12-ene-3b,22a,24-triol (12). A slurry of PCC
(0.97 g, 4.5 mmol) in dry CH2Cl2 (15 ml) was added to a
solution of 3 (1.5 g, 3.0 mmol) in dry CH2Cl2 (15 ml) at
room temperature, and the whole mixture then turned
dark. After stirring for 1.5 h, the reaction mixture was
diluted with EtOAc and filtered through a short column
of silica gel. The filtrate was then concentrated in vacuo
and purified by column chromatography on silica gel
(n-hexane/EtOAc, 15:1) to furnish the ketone 10
(1.0 g, 68%) as a white powder.
The crude tosylate (65 mg) was treated with 1.0 M THF
solution of lithium triethylborohydride (2 ml) at 65 ꢁC
for 1 h. After cooling to room temperature, the mixture
was added with water and extracted with EtOAc. The
organic layer was dried over MgSO4, filtered, and con-
centrated in vacuo. The residue was purified by flash
chromatography on silica gel (n-hexane/EtOAc, 10:1)
to afford the olefin 15 (38 mg, 79%) as a white solid.
A solution of sodium (70 mg, 3.0 mmol) in toluene
(3 ml) was heated to reflux. After vigorous stirring for
40 min, a solution of 10 (500 mg, 1.0 mmol) in BuOH
t
(5 ml) and toluene (3 ml) was added, and the whole mix-
ture was stirred under reflux. After 5 h, additional so-
dium (130 mg, 5.7 mmol) was added, and the reaction