Epoxides, Sulfites, and Sulfate from Triterpenoids
NaBH3CN, and this mixture was maintained with stirring at
115 °C for 2 h and 30 min. Small amounts of toluene were
added to remove DMF, with evaporation at reduced pressure,
and the residue was extracted with CH2Cl2, washed with
water, dried over anhydrous Na2SO4, and evaporated to give
a mixture of compounds. These compounds were chromato-
graphed on a silica gel column to yield the same products of
the previous reduction reaction in similar proportions.
756 cm-1 1 H NMR (CDCl3) δ 5.26 (1H, dd, J ) 3.6 Hz, H-12),
;
4.57 (1H, ddd, J ) 4.2, 10.7, 12.8 Hz, H-2â), 3.60 (3H, s,
COOCH3), 3.32 (1H, dd, J ) 3.4, 10.7 Hz, H-3R), 2.84 (1H, dd,
J ) 4.2, 13.8 Hz, H-18â), 2.41 (1H, dd, J ) 4.2, 12.9 Hz, H-1â),
1.11 (3H, s, Me), 1.08 (3H, s, Me), 0.94 (3H, s, Me), 0.91 (3H,
s, Me), 0.86 (3H, s, Me), 0.82 (3H, s, Me), 0.69 (3H, s, Me); for
13C NMR (CDCl3) see Table S-2 and spectrum S-16 in the
Supporting Information; HRLSIMS m/z calcd for C31H49O3INa
619.2624, found 619.2628. Data for 23: syrup; [R]25 ) 66 (c
D
Red u ction of Su lfa te 7 w ith AlLiH4. Product 7 (150 mg,
0.3 mmol) was dissolved in 3 mL of THF, 1 mL of a 0.1 M
solution of AlLiH4 in THF was added, and the mixture was
maintained at room temperature for 3 h. This mixture was
diluted with CH2Cl2, washed with water, dried with anhydrous
Na2SO4, and evaporated. Chromatography over silica gel
yielded 93 mg of 17 (59%) and 52 mg of 18 (38%). Data for 17:
1
1, CHCl3); IR (CHCl3) 3402, 2943, 1723, 1124 cm-1; H NMR
(CDCl3) δ 5.29 (1H, dd, J ) 3.6 Hz, H-12), 4.73 (1H, d, J ) 4.8
Hz, H-3R), 4.01 (1H, ddd, J ) 4.8, 9.4, 10.5 Hz, H-2â), 3.61
(3H, s, COOCH3), 2.85 (1H, dd, J ) 4.5, 14.4 Hz, H-18â), 1.14
(3H, s, Me), 1.12 (3H, s, Me), 1.09 (3H, s, Me), 1.03 (3H, s,
Me), 0.91 (3H, s, Me), 0.89 (3H, s, Me), 0.71 (3H, s, Me); for
13C NMR (CDCl3) see Table S-2 and spectrum S-17 in the
Supporting Information; HRLSIMS m/z calcd for C31H49O3INa
619.2624, found 619.2623.
white solid; mp 141-142 °C; [R]25 ) 48 (c 1, CHCl3); IR
D
(CHCl3) 3420, 2949, 1380, 1211 cm-1; 1H NMR (CDCl3) δ 5.18
(1H, dd, J ) 3.6 Hz, H-12), 4.90 (1H, ddd, J ) 4.2, 10.4, 11.2
Hz, H-2), 4.28 (1H, d, J ) 10.4 Hz, H-3R), 3.52 (1H, d, J )
10.9 Hz, H-28), 3.19 (1H, d, J ) 10.9 Hz, H-28), 2.23 (1H, dd,
J ) 4.2, 11.8 Hz, H-1R), 1.16 (3H, s, Me), 1.12 (3H, s, Me),
1.10 (3H, s, Me), 1.00 (3H, s, Me), 0.95 (3H, s, Me), 0.88 (3H,
s, Me), 0.87 (3H, s, Me); for 13C NMR (CDCl3) see Table S-2
and spectrum S-13 in the Supporting Information; HRLSIMS
m/z calcd for C30H48O5SNa 543.3120, found 543.3129. Data for
Red u ction of 8 w ith WCl6 a n d n -Bu Li. A solution of 160
mg of WCl6 (0.4 mmol) in 5 mL of THF was cooled at -70 °C,
and 0.08 mL of a 1.6 M solution in hexane of n-BuLi (0.8 mmol)
was added. The mixture was cooled to room temperature, 100
mg of 8 in 5 mL of THF was added, and the resulting mixture
was maintained with stirring at room temperature for 20 min.
Then 20 mL of a solution of NaOH (20%) was added and
extracted with CH2Cl2. The organic layer was washed twice
with water, dried with anhydrous Na2SO4, and evaporated.
The resulting residue was chromatographed on a silica gel
column to yield 7 mg of 21 (8%) and 46 mg of 24 (46%): yellow
18 (38%): white solid; mp 137-139 °C; [R]25 ) 115 (c 1,
D
CHCl3); IR 3385, 2947, 1460, 1046 (CHCl3) cm-1
;
H NMR
1
(CDCl3) δ 5.18 (1H, dd, J ) 3.6 Hz, H-12), 3.68 (1H, ddd, J )
4.5, 9.5, 11.3 Hz, H-2â), 3.54 (1H, d, J ) 11.0 Hz, H-28) 3.19
(1H, d, J ) 11.0 Hz, H-28), 2.99 (1H, d, J ) 9.5 Hz, H-3), 1.15
(3H, s, Me), 1.02 (3H, s, Me), 0.98 (3H, s, Me), 0.92 (3H, s,
Me), 0.87 (3H, s, Me), 0.86 (3H, s, Me), 0.81 (3H, s, Me); for
13C NMR (CDCl3) see Table S-2 and spectrum S-14 in the
Supporting Information; HRLSIMS m/z calcd for C30H50O3Na
481.3658, found 481.3656.
R ed u ct ive Op en in g of E p oxid e 8 w it h Na BH 3CN.
Product 8 (150 mg, 0.3 mmol) was dissolved in 9 mL of THF,
and 120 mg of NaBH3CN (1.8 mmol) was added. A solution of
0.3 mL of CF3COOH in 6 mL of THF was added, and the
resulting mixture was stirred at several temperatures for
different times. Trifluoroacetic acid was neutralized with
NaHCO3, and the mixture was washed with water, extracted
with CH2Cl2, dried with anhydrous Na2SO4, and evaporated.
Chromatography over silica gel yielded different products (3
and 4) in different amounts (see Table 1).
solid; mp 185-187 °C; [R]25 ) 50 (c 1, CHCl3); IR (CHCl3)
D
3404, 2947, 1724, 1125 cm-1
;
H NMR (CDCl3) δ 5.27 (1H,
1
dd, J ) 3.6 Hz, H-12), 4.57 (1H, ddd, J ) 4.3, 10.2, 12.2 Hz,
H-2â), 3.61 (3H, s, COOCH3), 3.17 (1H, d, J ) 10.2 Hz, H-3R),
2.85 (1H, dd, J ) 4.5, 13.8 Hz, H-18â), 1.12 (3H, s, Me), 1.08
(3H, s, Me), 0.96 (3H, s, Me), 0.91 (3H, s, Me), 0.89 (3H, s,
Me), 0.83 (3H, s, Me), 0.70 (3H, s, Me); for 13C NMR (CDCl3)
see Table S-2 and spectrum S-18 in the Supporting Informa-
tion; HRLSIMS m/z calcd for C31H49O3ClNa 527.3268, found
527.3269.
Tr ea tm en t of 8 w ith Na Cl. To a mixture of 50 mg of 8
(0.1 mmol) in 10 mL of THF and diluted sulfuric acid was
added 25 mg of NaCl (0.4 mmol). The resulting mixture was
stirred at reflux for 1 h. Then the reaction mixture was
neutralized with a diluted solution of NaHCO3, washed with
water, extracted with CH2Cl2, and evaporated at reduced
pressure. The resulting residue was chromatographed on a
silica gel column to provide 45 mg of 24 (89%) and 5 mg of 25
Red u ctive Op en in g of Ep oxid e 8 w ith AlLiH4. Product
8 (150 mg, 0.3 mmol) was dissolved in 1 mL of a 0.1 M solution
of AlLiH4 in THF, and the mixture was maintained with
stirring under different conditions (Table 1). After 1 h, the
reaction mixture was evaporated at reduced pressure, and the
resulting residue was chromatographed on a silica gel column
to obtain 3, 4, 19,15 and 20 in different quantities (see Table
(10%): white solid; mp 151-153 °C; [R]25 ) 74 (c 1, CHCl3);
D
IR (CHCl3) 3395, 2925, 1112 cm-1
;
1H NMR (CDCl3) δ 5.29
(1H, dd, J ) 3.9 Hz, H-12), 4.22 (1H, d, J ) 10.6 Hz, H-3R),
3.86 (1H, ddd, J ) 4.4, 10.6, 12.4 Hz, H-2â), 3.61 (3H, s,
COOCH3), 2.85 (1H, dd, J ) 4.1, 13.9 Hz, H-18â), 1.12 (3H, s,
Me), 1.09 (3H, s, Me), 1.04 (3H, s, Me), 1.02 (3H, s, Me), 0.92
(3H, s, Me), 0.89 (3H, s, Me), 0.71 (3H, s, Me); for 13C NMR
(CDCl3) see Table S-2 and spectrum S-19 in the Supporting
Information; HRLSIMS m/z calcd for C31H46O3ClNa 527.3268,
found 527.3270.
1). Data for 20: syrup; [R]25 ) 98 (c 1, CHCl3); IR (CHCl3)
D
1
3417, 2948, 2867, 756 cm-1
;
H NMR (CDCl3) δ 5.19 (1H, dd,
J ) 3.6 Hz, H-12), 3.52 (1H, d, J ) 10.8 Hz, H-28), 3.22 (1H,
dd, J ) 2.0, 3.9 Hz, H-2R), 3.19 (1H, d, J ) 10.8 Hz, H-28),
2.81 (1H, dd, J ) 4.0 Hz, H-3R), 1.13 (3H, s, Me), 1.07 (3H, s,
Me), 1.07 (3H, s, Me), 0.99 (3H, s, Me), 0.91 (3H, s, Me), 0.87
(3H, s, Me), 0.86 (3H, s, Me); for 13C NMR (CDCl3) see Table
S-2 and spectrum S-15 in the Supporting Information;
HRLSIMS m/z calcd for C30H48O2Na 463.3552, found 463.3544.
Tr ea tm en t of 8 w ith KBr . To a mixture of 50 mg of 8 (0.1
mmol) in 10 mL of THF and diluted sulfuric acid was added
50 mg of KBr (0.4 mmol), and the resulting mixture was
maintained at reflux for 1 h. Then the reaction mixture was
neutralized with a diluted solution of NaHCO3, washed with
water, extracted with CH2Cl2, and evaporated at reduced
pressure. Chromatography over silica gel yielded 47 mg of 26
(85%) and 8 mg of 27 (15%). Data for 26: white solid; mp 170-
Op en in g of 8 w ith I2 a n d P P h 3. To a mixture of 51 mg of
I2 (0.2 mmol), 53 mg of triphenylphosphine (0.2 mmol), and 7
mL of CH2Cl2 was added a solution of product 8 (150 mg, 0.3
mmol) in 3 mL of CH2Cl2. The resulting mixture was stirred
for 30 min at different temperatures (Table 2). When the
reaction was finished, the mixture was washed with a diluted
solution of Na2S2O3‚5H2O, extracted with CH2Cl2, dried over
anhydrous Na2SO4, and evaporated. Depending on the condi-
tions (see Table 2), chromatography over silica gel yielded
different amounts of 21,13a 22, and 23. Data for 22: syrup;
172 °C; [R]25 ) 23 (c 1, CHCl3); IR (CHCl3) 3356, 2931, 1609,
D
1117 cm-1
;
1 H NMR (CDCl3) δ 5.26 (1H, dd, J ) 3.6 Hz, H-12),
4.35 (1H, ddd, J ) 4.3, 10.4, 12.4 Hz, H-2â), 3.61 (3H, s,
COOCH3), 3.27 (1H, dd, J ) 2.0, 10.4 Hz, H-3R), 2.85 (1H, dd,
J ) 4.5, 13.9 Hz, H-18â), 1.12 (3H, s, Me), 1.09 (3H, s, Me),
0.96 (3H, s, Me), 0.91 (3H, s, Me), 0.89 (3H, s, Me), 0.83 (3H,
s, Me), 0.70 (3H, s, Me); for 13C NMR (CDCl3) see Table S-2
[R]25 ) 22 (c 1, CHCl3); IR (CHCl3) 3424, 2946, 1722, 1162,
D
J . Org. Chem, Vol. 68, No. 12, 2003 4843