+
MS ES PI (m/z): [M + Na] 555.4. MS ES NI (m/z): [M - H]− 531.2.
PMRspectrum (400 MHz, CDCl , δ, ppm, J/Hz, 0 = HMDS): 0.32 and 0.47 (2H-19, d, J = 4.4), 0.89, 0.98, 1.06, 1.07,
2
3
3
3
3
2
1.15, 1.19, 1.23 (7 × CH , s), 1.99 (CH COO, s), 2.27 (H-17, d, J = 7.6), 2.52 (H-22, q, J = J = J = 10), 3.45 (H-6, td,
J = J = 9.7, J = 3.2), 3.68 (H-24, t, J = J = 7.5), 4.50 (H-3, dd, J = 11, J = 4.7), 4.62 (H-16, q, J = J = J =
3
3
1
2
3
3
3
3
3
3
3
3
3
3
1
2
3
1
2
1
2
1
2
3
13
7.5). Table 1 gives the C NMR spectrum.
Further elution of the column by system 1 gave 1 (4 mg).
6-Acetoxy-20R,24S-epoxycycloartan-25-ol-3,16-dione (5), 6-Acetoxy-20R,24S-epoxycycloartan-3β,25-diol-16-one
(6), and 6-Acetoxy-20R,24S-epoxycycloartan-16β,25-diol-3-one (7) from 4. Monoacetate 4 (550 mg) in acetone (100 mL)
at −8°C was treated with Jones reagent (0.5 mL) [5] and stirred for 35 min. The excess of oxidant was destroyed by adding
several milliliters of methanol to the mixture. The solution was poured into water. The products were extracted with CHCl .
3
The usual workup and evaporation of CHCl followed byseparation over a column with elution bysystem 3 isolated 5 (128 mg),
3
C H O , mp 126-128°C (methanol).
32 48
6
IR spectrum (KBr, ν, cm−1): 3432 (OH), 1737 (>C=O on C-16), 1706 (>C=O on C-3), 1737, 1243 (ester).
+
MS ES PI (m/z): [M + Na] 551.3. MS ES NI (m/z): [M - H]− 527.1.
2
PMR spectrum (400 MHz, CDCl , δ, ppm, J/Hz, 0 = HMDS): 0.50 and 0.73 (2H-19, d, J = 4.7), 1.04, 1.08, 1.08, 1.11,
3
3
3
3
1.14, 1.15, 1.19 (7 × CH , s), 1.97 (CH COO, s), 2.19 (H-5, d, J = 10), 2.84 (H-17, s), 3.67 (H-24, dd, J = 8.3, J = 6), 4.66
(H-6, td, J = J = 10, J = 3.7). Table 1 gives the C NMR spectrum.
3
3
1
2
3
3
3
13
1
2
3
Further elution of the column by the same solvent system isolated 6 (41 mg), C H O , mp 133-135°C (system 3),
32 50
6
solidifying at 145-150°C, melting at 175-177°C.
IR spectrum (KBr, ν, cm−1): 3449 (OH), 3047 (cycloartane CH ), 1730 (>C=O on C-16), 1730, 1248 (ester).
2
+
MS ES PI (m/z): [M + Na] 553.3. MS ES NI (m/z): [M - H]− 529.1.
2
PMR spectrum (400 MHz, CDCl , δ, ppm, J/Hz, 0 = HMDS): 0.35 and 0.56 (2H-19, d, J = 4.8), 0.86, 0.93, 1.04
3
4
3
(3 × CH , s), 1.07 (CH -28, d, J = 0.8), 1.12, 1.13, 1.19 (3 × CH , s), 1.65 (H-5, d, J = 9.9), 1.94 (CH COO, s), 2.06 (H-15β,
dq, J = 18, J = 0.8), 2.84 (H-17, s), 3.26 (H-3, dd, J = 11, J = 4.5), 3.67 (H-24, dd, J = 8.3, J = 5.8), 4.69 (H-6, td,
3
3
3
3
2
4
3
3
3
3
1
2
1
2
3
3
3
13
J = J = 9, J = 4.3). Table 1 gives the C NMR spectrum.
1
2
3
Further elution of the column with the same system gave monoketone 7 (135 mg), C H O , mp 111-114°C
32 50
6
(system 3).
IR spectrum (KBr, ν, cm−1): 3424 (OH), 1734, 1245 (ester), 1702 (>C=O on C-3).
+
MS ES PI (m/z): [M + Na] 553.4. MS ES NI (m/z): [M - H]− 531.4.
PMR spectrum (400 MHz, CDCl , δ, ppm, J/Hz, 0 = HMDS): 0.43 and 0.71 (2H-19, d, J = 4.5), 0.89, 1.08, 1.09, 1.10,
2
3
3
3
1.17, 1.22, 1.25 (7 × CH , s), 1.97 (CH COO, s), 2.14 (H-5, d, J = 10), 2.27 (H-17, d, J = 7.9), 2.50 (2H-2, 1H-22, m), 3.70
3
3
3
3
3
3
3
3
3
3
(H-24, t, J = J = 7.2), 4.62 (H-16, td, J = J = 7.9, J = 6.3), 4.68 (H-6, td, J = J = 10, J = 3.6). Table 1 gives the
1
2
1
2
3
1
2
3
13
C NMR spectrum.
Cycloadsurgenin (8), 17E,24S-Cycloart-17-en-6α,24,25-triol-3,16-dione (9), and 17Z,24S-Cycloart-17-en-
6α,24,25-triol-3,16-dione (10) from 5. Monoacetate 5 (50 mg) was hydrolyzed by methanolic NaOH (10 mL, 0.1%) for 2 d
at room temperature. The mixture was poured into water and treated with ethylacetate. The ethylacetate extract was washed
with water and evaporated. The solid was chromatographed over a column with elution by system 2 to isolate 8 (15 mg),
C H O , mp 243-247°C (CHCl :CH OH, 1:1).
30 46
5
3
3
IR spectrum (KBr, ν, cm−1): 3410, 3367 (OH), 1726 (>C=O on C-16), 1702 (>C=O on C-3).
+
MS ES PI (m/z): [M + Na] 509.3. MS ES NI (m/z): [M - H]− 485.1.
PMR spectrum (600 MHz, CDCl , δ, ppm, J/Hz, 0 = HMDS): 0.45 and 0.66 (2H-19, d, J = 4.2), 1.08, 1.15, 1.16, 1.17,
2
3
3
3
3
3
3
1.20, 1.23, 1.37 (7 × CH , s), 2.92 (H-17, s), 3.50 (H-6, td, J = J = 9.6, J = 4.8), 3.71 (H-24, dd, J = 8.4, J = 6).
Table 1 gives the C NMR spectrum.
3
1
2
3
1
2
13
Further elution of the column with the same solvent system produced 9 and 10 (5 mg of the mixture, 0.6:1 according
to the integrated intensities in the PMR spectrum).
2
PMR spectrum of 9 (400 MHz, CDCl , δ, ppm, J/Hz, 0 = HMDS): 0.43 and 0.64 (2H-19, d, J = 4), 0.978 (CH -28,
3
3
4
3
3
d, J = 1.3), 1.09, 1.12, 1.18, 1.300, 1.305 (5 × CH , s), 2.12 (CH -21, s), 3.28 (H-24, dd, J = 10.6, J = 1.9), 3.51 (H-6, td,
3
3
1
2
3
3
3
J = J = 10.8, J = 3.2).
1
2
3
736