3.2 Experimental Procedures
47
(m, 4 H, H
1b,7a,22 ), 1.53 (dd, J = 12.9, 2.0 Hz, 1 H, H
6b ), 1.52–1.41 (m, 5 H,
H
5,6a,27 ), 1.39–1.32 (m, 2 H, H
21 ), 1.32–1.19 (m, 6 H, H
7b,15b,16b,26 ), 1.10
(s, 3 H, H
23 ), 1.04 (s, 3 H, H
24 ), 1.00 (s, 3 H, H
29 ), 0.96 (s, 3 H, H
25 ), 0.90
(s, 3 H, H
30 ).
13 C-NMR (150 MHz, CDCl 3 ): δ 217.9 (C
3 ), 179.0 (C
28 ),
91.8 (C
13 ), 56.3 (C
12 ), 54.6 (C
5 ), 52.5 (C
18 ), 47.3 (C
4 ), 45.6 (C
17 ), 44.9
(C
9 ), 43.6 (C
14 ), 42.4 (C
8 ), 40.1 (C
19 ), 39.2 (C
1 ), 36.4 (C
10 ), 34.1 (C
7 ), 34.0
(C
21 ), 33.9 (C
2 ), 33.4 (C
30 ), 32.0 (C
20 ), 31.0 (C
11 ), 29.3 (C
15 ), 27.6 (C
22 ),
27.1 (C
23 ), 23.7 (C
29 ), 21.4 (C
16 ), 21.1 (C
27 ), 21.0 (C
24 ), 19.2 (C
6 ), 18.8
(C
26 ), 17.2 (C
25 ). [α]
20
D +84.0 (c 1.0, CDCl 3 ). HRMS (ESI-TOF) m/z:
[M + Na]
+ Calcd for C 30 H 45 ClNaO 3
+ 555.2444; Found 555.2439.
3.2.5 12α-Chloro-3-(hydroxyimino)-olean-28,13β-olide
(6a)
N
H
H
H
Cl
O
O
1
2
3
4
5
6
7
8
9
10
11
12 13
14
15
16
17
18
19
20
21
22
28
24
23
25
26
29
27
30
HO
A round bottom flask, equipped with magnetic stirring bar, was charged
with a solution of oleanolic acid (5) (1.00 mmol, 457 mg, 1.00 equiv) in DCM
(12 ml) and pyridine (15.2 mmol, 1229 μl, 15.2 equiv). After addition of trichloroisocyanuric acid (0.80 mmol, 186 mg, 0.80 equiv) was added, and the
mixture was left stirring at 20 °C for 90 min. Then i-PrOH (0.80 mmol, 61 μl,
0.80 equiv) was added, and the mixture was left stirring at 20 °C for 30 min.
Subsequently, hydroxylamine hydrochloride (3.2 mmol, 222 mg, 3.2 equiv)
was added, and the reaction was left stirring at 20 °C for 19 h. The solution
was diluted with DCM (8 ml), filtered over a glass frit (P 16) and the residue
was washed with DCM (2 × 2 ml). The organics were washed with HCl
solution (1 m in H 2 O) (3 × 12 ml). After drying over MgSO 4 the solution
was concentrated under reduced pressure. The residue was dried in vacuo
47
(m, 4 H, H
1b,7a,22 ), 1.53 (dd, J = 12.9, 2.0 Hz, 1 H, H
6b ), 1.52–1.41 (m, 5 H,
H
5,6a,27 ), 1.39–1.32 (m, 2 H, H
21 ), 1.32–1.19 (m, 6 H, H
7b,15b,16b,26 ), 1.10
(s, 3 H, H
23 ), 1.04 (s, 3 H, H
24 ), 1.00 (s, 3 H, H
29 ), 0.96 (s, 3 H, H
25 ), 0.90
(s, 3 H, H
30 ).
13 C-NMR (150 MHz, CDCl 3 ): δ 217.9 (C
3 ), 179.0 (C
28 ),
91.8 (C
13 ), 56.3 (C
12 ), 54.6 (C
5 ), 52.5 (C
18 ), 47.3 (C
4 ), 45.6 (C
17 ), 44.9
(C
9 ), 43.6 (C
14 ), 42.4 (C
8 ), 40.1 (C
19 ), 39.2 (C
1 ), 36.4 (C
10 ), 34.1 (C
7 ), 34.0
(C
21 ), 33.9 (C
2 ), 33.4 (C
30 ), 32.0 (C
20 ), 31.0 (C
11 ), 29.3 (C
15 ), 27.6 (C
22 ),
27.1 (C
23 ), 23.7 (C
29 ), 21.4 (C
16 ), 21.1 (C
27 ), 21.0 (C
24 ), 19.2 (C
6 ), 18.8
(C
26 ), 17.2 (C
25 ). [α]
20
D +84.0 (c 1.0, CDCl 3 ). HRMS (ESI-TOF) m/z:
[M + Na]
+ Calcd for C 30 H 45 ClNaO 3
+ 555.2444; Found 555.2439.
3.2.5 12α-Chloro-3-(hydroxyimino)-olean-28,13β-olide
(6a)
N
H
H
H
Cl
O
O
1
2
3
4
5
6
7
8
9
10
11
12 13
14
15
16
17
18
19
20
21
22
28
24
23
25
26
29
27
30
HO
A round bottom flask, equipped with magnetic stirring bar, was charged
with a solution of oleanolic acid (5) (1.00 mmol, 457 mg, 1.00 equiv) in DCM
(12 ml) and pyridine (15.2 mmol, 1229 μl, 15.2 equiv). After addition of trichloroisocyanuric acid (0.80 mmol, 186 mg, 0.80 equiv) was added, and the
mixture was left stirring at 20 °C for 90 min. Then i-PrOH (0.80 mmol, 61 μl,
0.80 equiv) was added, and the mixture was left stirring at 20 °C for 30 min.
Subsequently, hydroxylamine hydrochloride (3.2 mmol, 222 mg, 3.2 equiv)
was added, and the reaction was left stirring at 20 °C for 19 h. The solution
was diluted with DCM (8 ml), filtered over a glass frit (P 16) and the residue
was washed with DCM (2 × 2 ml). The organics were washed with HCl
solution (1 m in H 2 O) (3 × 12 ml). After drying over MgSO 4 the solution
was concentrated under reduced pressure. The residue was dried in vacuo