6
H.-B. Dong et al.
epi-muricatacin (4S, 5R)-8 as a colorless
needle crystal (0.44 g, 78%), m.p. 70.0–
0.5 mmol) were added into a 50-ml
round-bottom flask. The mixture was
stirred for 30 min at room temperature
and then filtered. The solvent was removed
under reduced pressure, and the residue
was purified by chromatography on silica
gel (4:1 (v/v) hexanes/EtOAc) to afford
0.24 g of (þ)-muricatacin 1 in 85% yield
as a white solid, m.p. 67.8–68.88C,
2
5
{
0.88C, ½aꢀ þ 15.1 (c ¼ 1.2, CHCl ).
D
3
2
D
5
lit.[12] m.p. 71–738C, ½aꢀ þ 16.6
1
(
c ¼ 0.78, CHCl )}. H NMR (CDCl ) d:
3
3
4
2
.46–4.41 (m, 1H), 3.93 (br, 1H), 2.61–
.51 (m, 2H), 2.30–2.12 (m, 2H), 1.96 (d,
J ¼ 3.4 Hz, 1H), 1.55–1.26 (m, 22H), 0.88
1
3
(
t, J ¼ 6.7 Hz, 3H). C NMR (CDCl ) d:
3
2
5
1
77.5, 82.8, 71.4, 31.9 (2 £ C), 29.6 (2
D
3
2
D
5
£
C), 29.5 (3 £ C), 29.3, 28.7, 25.6, 22.6,
m.p. 68–708C, ½aꢀ þ 22.4 (c ¼ 0.42,
1
CHCl )}. H NMR (CDCl ) d: 4.44–4.38
2
1.1, 14.1. HR-ESI-MS: m/z 307.2245
(calcd for C H O Na,
07.2244).
3
3
þ
[
M þ Na]
(m, 1H), 3.59–3.55 (m, 1H), 2.63–2.47
(m, 2H), 2.26–2.09 (m, 2H), 1.84 (d,
J ¼ 6.0 Hz, 1H), 1.56–1.26 (m, 22H), 0.88
1
7
32
3
3
1
3
(
t, J ¼ 6.7 Hz, 3H). C NMR (CDCl ) d:
3
3
.2.7 (4S, 5S)-Lactone 4-nitrobenzoate 9
1
77.1, 82.9, 73.6, 33.0, 31.9, 29.6 (2 £ C),
Under the atmosphere of nitrogen, 25 ml of
dry THF was added into a 50-ml round-
bottom flask. It was cooled to 08C, and
then triphenylphosphine (1.05 g, 4 mmol)
and diethyl azodicarboxylate (DEAD,
29.5 (2 £ C), 29.3, 28.7, 25.4, 24.7, 22.7,
14.1. HR-ESI-MS: m/z 307.2246
(calcd for C H O Na,
17 32 3
þ
[M þ Na]
307.2244).
0
.59 g, 4 mmol) were added, followed by
4S, 5R)-8 (0.28 g, 1 mmol) and p-nitro-
(
Acknowledgments
benzoic acid (0.20 g, 1.2 mmol). The
mixture was stirred at room temperature
for 4 h. The solvent was removed under
reduced pressure and the residue was
purified by chromatography on silica gel
This project was co-founded by the National
Key Technologies R&D Program (No.
2
011BAE06B04), National Hi-Tech R & D
Program of China (No. 2011AA10A202), and
Natural Science Foundation of China (No.
2
1172254).
(10:1 to 5:1 (v/v) petroleum ether–EtOAc)
to afford 0.35 g (81% yield) of (4S, 5S)-
lactone 4-nitrobenzoate compound 9 as a
References
1
light yellow oil. H NMR (CDCl ) d:
3
[1] J.R. Matthew, F.K. John, V.W. Karl, and
J.L. McLaughlin, Tetrahedron Lett. 32,
8
5
2
1
0
.33–8.28 (m, 2H), 8.24–8.19 (m, 2H),
.35–5.29 (m, 1H), 4.80–4.74 (m, 1H),
.59–2.40 (m, 3H), 2.10–2.05 (m, 1H),
.87–1.80 (m, 2H), 1.43–1.23 (m, 20H),
1
137 (1991).
2] H. Makabe, Biosci. Biotech. Biochem. 71,
367 (2007).
3] Q.F. Alali, X.X. Liu, and J.L. Mclaughlin,
J. Nat. Prod. 62, 504 (1999).
[
[
2
1
3
.86 (t, J ¼ 6.7 Hz, 3H).
C NMR
(CDCl ) d: 176.2, 163.9, 150.5, 134.8,
3
[4] M.C. Zafra-Polo, B. Figadere, T. Gal-
lardo, R.J. Jose, and D. Cortes, Phyto-
chemistry 48, 1087 (1998).
1
30.7, 123.4, 79.7, 76.0, 31.6, 30.4, 29.4
(
2 £ C), 29.3, 29.2, 29.1 (2 £ C), 27.9,
[
5] M.C. Murcia, C. Navarro, and A. Moreno,
Curr. Org. Chem. 14, 15 (2010).
2
4
4.9, 23.9, 22.4, 13.8. HR-ESI-MS: m/z
56.2360 [M þ Na]
þ
(calcd for
[
6] G. Maria, G. Zoila, M. Andrea, G. Gomez,
and F. Yagamare, Synthesis 45, 1693
C H NO Na, 456.2362).
6
2
4
35
(
7] G. Maria, G. Zoila, P. Gonzalo, G.
2013).
[
Gomez, and F. Yagamare, Synthesis 45,
6
3
.2.8 (þ)-Muricatacin 1
25 (2013).
[8] B. Sreco, G. Benedekovic, M. Popsavin,
P. Hadzic, V. Kojic, G. Bogdanovic,
Here, 15 ml of CH OH, K CO (0.35 g,
3
3
2
2
.5 mmol) and compound 9 (0.22 g,