3.2 Experimental Procedures
45
3.2.3 12α-Chloro-3-oxo-olean-28,13β-olide (27a)
O
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
A round bottom flask, equipped with magnetic stirring bar, was charged
with a suspension of oleanolic acid (5) (1.00 mmol, 457 mg, 1.00 equiv) in
EtOAc (16 ml) and pyridine (2.40 mmol, 194 μl, 2.40 equiv). After addition
of a solution of trichloroisocyanuric acid (0.80 mmol, 186 mg, 0.80 equiv) in
EtOAc (2 ml) the mixture was left stirring at 20 °C for 2 h. The solution
was filtered over a glass frit (P 16) and the residue was washed with EtOAc
(2 ml). The organics were washed with HCl solution (1 m in H 2 O) (5 ml),
NaHCO 3 solution (saturated in H 2 O) (5 ml) and NaCl solution (saturated
in H 2 O) (5 ml). After drying over MgSO 4 the solution was concentrated
under reduced pressure. The residue was dried in vacuo to give the target
compound as colourless foam (quantitative yield).
1
H-NMR (600 MHz, CDCl 3 ): δ 4.19 (dd, J = 3.8, 2.4 Hz, 1 H, H
12 ), 2.50
(dd, J = 8.7, 6.4 Hz, 2 H, H
2 ), 2.30 (ddd, J = 14.7, 12.6, 3.8 Hz, 1 H, H
11a ),
2.20–2.13 (m, 2 H, H
16a,19a ), 2.06–1.99 (m, 2 H, H
18,19b ), 1.99–1.89 (m, 2 H,
H
1a,15a ), 1.85 (dd, J = 12.6, 2.0 Hz, 1 H, H
9 ), 1.74 (dt, J = 14.8, 2.2 Hz, 1 H,
H
11b ), 1.65 (dd, J = 9.0, 3.5 Hz, 2 H, H
22ab ), 1.62–1.44 (m, 5 H, H
1b,5,6ab,7a ),
1.40 (s, 3 H, H
27 ), 1.38–1.32 (m, 2 H, H
21ab ), 1.32–1.26 (m, 2 H, H
7b,16b ),
1.24 (s, 4 H, H
15b,26 ), 1.10 (s, 3 H, H
23 ), 1.04 (s, 3 H, H
24 ), 1.00 (s, 3 H, H
29 ),
0.97 (s, 3 H, H
25 ), 0.91 (s, 3 H, H
30 ).
13 C-NMR (150 MHz, CDCl 3 ): δ
217.8 (C
3 ), 179.1 (C
28 ), 91.7 (C
13 ), 65.0 (C
12 ), 54.6 (C
5 ), 52.1 (C
18 ), 47.3
(C
4 ), 45.4 (C
17 ), 44.2 (C
9 ), 43.2 (C
14 ), 42.3 (C
8 ), 39.9 (C
19 ), 39.4 (C
1 ), 36.3
(C
10 ), 34.0 (C
21 ), 34.0 (C
2 ), 33.9 (C
7 ), 33.4 (C
29 ), 32.0 (C
20 ), 29.9 (C
11 ),
29.1 (C
15 ), 27.6 (C
22 ), 27.1 (C
23 ), 23.7 (C
30 ), 21.4 (C
16 ), 21.1 (C
24 ), 20.2
(C
27 ), 19.2 (C
6 ), 18.6 (C
26 ), 17.0 (C
25 ). [α]
20
D +76.4 (c 1.0, CDCl 3 ). IR
45
3.2.3 12α-Chloro-3-oxo-olean-28,13β-olide (27a)
O
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
A round bottom flask, equipped with magnetic stirring bar, was charged
with a suspension of oleanolic acid (5) (1.00 mmol, 457 mg, 1.00 equiv) in
EtOAc (16 ml) and pyridine (2.40 mmol, 194 μl, 2.40 equiv). After addition
of a solution of trichloroisocyanuric acid (0.80 mmol, 186 mg, 0.80 equiv) in
EtOAc (2 ml) the mixture was left stirring at 20 °C for 2 h. The solution
was filtered over a glass frit (P 16) and the residue was washed with EtOAc
(2 ml). The organics were washed with HCl solution (1 m in H 2 O) (5 ml),
NaHCO 3 solution (saturated in H 2 O) (5 ml) and NaCl solution (saturated
in H 2 O) (5 ml). After drying over MgSO 4 the solution was concentrated
under reduced pressure. The residue was dried in vacuo to give the target
compound as colourless foam (quantitative yield).
1
H-NMR (600 MHz, CDCl 3 ): δ 4.19 (dd, J = 3.8, 2.4 Hz, 1 H, H
12 ), 2.50
(dd, J = 8.7, 6.4 Hz, 2 H, H
2 ), 2.30 (ddd, J = 14.7, 12.6, 3.8 Hz, 1 H, H
11a ),
2.20–2.13 (m, 2 H, H
16a,19a ), 2.06–1.99 (m, 2 H, H
18,19b ), 1.99–1.89 (m, 2 H,
H
1a,15a ), 1.85 (dd, J = 12.6, 2.0 Hz, 1 H, H
9 ), 1.74 (dt, J = 14.8, 2.2 Hz, 1 H,
H
11b ), 1.65 (dd, J = 9.0, 3.5 Hz, 2 H, H
22ab ), 1.62–1.44 (m, 5 H, H
1b,5,6ab,7a ),
1.40 (s, 3 H, H
27 ), 1.38–1.32 (m, 2 H, H
21ab ), 1.32–1.26 (m, 2 H, H
7b,16b ),
1.24 (s, 4 H, H
15b,26 ), 1.10 (s, 3 H, H
23 ), 1.04 (s, 3 H, H
24 ), 1.00 (s, 3 H, H
29 ),
0.97 (s, 3 H, H
25 ), 0.91 (s, 3 H, H
30 ).
13 C-NMR (150 MHz, CDCl 3 ): δ
217.8 (C
3 ), 179.1 (C
28 ), 91.7 (C
13 ), 65.0 (C
12 ), 54.6 (C
5 ), 52.1 (C
18 ), 47.3
(C
4 ), 45.4 (C
17 ), 44.2 (C
9 ), 43.2 (C
14 ), 42.3 (C
8 ), 39.9 (C
19 ), 39.4 (C
1 ), 36.3
(C
10 ), 34.0 (C
21 ), 34.0 (C
2 ), 33.9 (C
7 ), 33.4 (C
29 ), 32.0 (C
20 ), 29.9 (C
11 ),
29.1 (C
15 ), 27.6 (C
22 ), 27.1 (C
23 ), 23.7 (C
30 ), 21.4 (C
16 ), 21.1 (C
24 ), 20.2
(C
27 ), 19.2 (C
6 ), 18.6 (C
26 ), 17.0 (C
25 ). [α]
20
D +76.4 (c 1.0, CDCl 3 ). IR