7
868 Jiang et al.
Asian J. Chem.
However, fuming sulfuric acid is a hazardous and corrosive
solution. We use chlorosulfonic acid in place of the fuming
sulfuric acid and use chloroform as the solvent, which can cut
the cost of acid. In a typical experiment, chlorosulfonic acid
three hours. After reaction, the product was filtered, analyzed
5 6 4
by means of a Shimadzu GC-MS, GC-MS calcd. For C H O ,
m/z 130.03, found 130. The dihydro-4-hydroxy-2H-pyran-
2,6(3H)-dione in chloroform was directly used in next step,
followed by charging of imidazole (6.5g), t-butyldimethylsilyl
chloride (13.5 g) under nitrogen atmosphere. Reaction mass
was maintained at 20-30 °C for 24 h, followed by washing the
reaction mass using water and brine. The product was extracted
with t-butylmethyl ether and concentrated to precipitate
3-[(tert-butyldimethylsilyl)oxy]glutaric anhydride. The
product was crystallized from cyclohexane and dried to obtain
(12 g) was placed in a 100 mL round-bottomed flask with a
drying tube. The flask was immediately cooled in an ice/salt
bath on a stirring plate and fine citric acid powder (19.2 g)
dissolve in 50 mL chloroform was gradually dropwise added.
The temperature was controlled to be less than 10 °C. The
citric acid dissolved into a clear solution in 0.5 h, then the
reaction temperature was gradually raised to room temperature
to allow evolution of CO gas. Once the foaming ceased, the
temperature of the reaction mixture was increased to 30 °C
for another 20 min to complete the reaction and promptly
returned to the ice/salt bath. When the bath temperature rises
to 5 °C over time, finely cracked ice cubes should be inter-
mittently added into the bath at around 5 °C for another 0.5 h.
The reaction mixture was then extracted with pre-cooled ethyl
acetate (100 mL × 3). The organic solution was dried over
1
89.7 % of a white crystalline solid with amp 80-81 °C, H
NMR( CDCl ), 2. 26 (d, 4H,
3
) 0. 08 (s, 6H, CH
3
), 1 (s, 9H, CH
3
CH ), 5 (m, H, CH). GC-MS calcd. For C11H O Si m/z 244.11,
2 20 4
found 244.10.
Conclusion
In summary, we report a new synthetic method for 3-[(tert-
butyldimethylsilyl)-oxy]glutaric anhydride utilizing a biore-
source precursor with the total yield of 77 % by four steps.
Each step is through crystallization or simple extraction and
without column chromatography. Additionally, the new syn-
thetic route also demonstrated a potential utilization of organic
bioresource in the synthesis of intermediate of rosuvastatin.
2 4
anhydrous Na SO and subsequently subjected to a rota-vapor
to remove organic solvent with a yield of 90.1 %. Pure acetone
dicarboxylic acid obtained is unstable. Therefore, it was
immediately used in the next step. Acetone dicarboxylic acid
(
14.6 g) was dehydrated with acetic anhydride (200 mL) for
h at 0 °C with stirring. The pale yellow precipitate was filtered,
3
ACKNOWLEDGEMENTS
washed with glacial acetic acid (300 mL) and then with
benzene (100 mL). The obtained white solid was characterized
as acetone dicarboxylic anhydride with the yield of 95.3 %,
The financial support from the Science and Technology
Department of Zhejiang Province of the People's Republic of
China (NO. 2011R09028-10) is gratefully acknowledged.
1
m.p. 137-138 °C, H NMR (400 MHz, DMSO-d
6
) δ 3.68 (s,
2
5 4 4
H), 5.23 (s, 1H), 12.5 (br s, 1H). GC-MS calcd. For C H O
REFERENCES
m/z 128.01, found 128.1. The acetone dicarboxylic acid
anhydride (11.5 g) just prepared was dissolved in chloroform
(80 mL), then performed in a 100 mL stainless steel autoclave.
1. F. McTaggart, L. Buckett, R. Davidson, G. Holdgate, A. McCormick,
D. Schneck, G. Smith and M. Warwick, Am. J. Cardiol., 87(suppl), 28B
(
2001).
G. Xu, G.L. Zuo, S.H. Zhong and W. Zhang, Lett. Org. Chem., 6, 419
2009).
0
.1 g 3 wt. % Ru/C (50.2 % water content, surface area of 789
2
2
.
m /g) was transferred into the autoclave. After the necessary
connection between the autoclave and hydrogen gas cylinder
(
3. V.K. Kansal, B.P. Chaurasia, H.K. Patel, V. Gothalia and H. Gandhi,
WO Patent 2008130638 (2008).
was duly made, H
pressure reached 1.0 MPa. H
few seconds to allow good mixing of H
2
gas passed into the autoclave until H
pressure was maintained for a
and air in the
2
4
.
A.E. Ponnuswamy, J.N. Jaware, H. Ranjan and V.K. Kansal, WO Patent
008130678 (2008).
D.S. Karanewsky, US Patent 4804770 (1989).
2
2
2
5
.
autoclave. Then the gas mixture in the autoclave was allowed
to expand. Pressurization and successive depressurization were
repeated 10 times so as to completely replace the air in the
6. P. Wipf and M. Grenon, Can. J. Chem., 84, 1226 (2006).
7
.
H.C.Wu,Y.S. Li,Y.C. Liu, S.-Y. Lyu, C.-J.Wu andT.-L. Li, ChemBioChem.,
3, 862 (2012).
C.J. Jiang, L.Q. Sheng and B. Gao, Zhejiang Keji Xueyuan Xuebao,
0, 107 (2008).
1
8
.
autoclave. The autoclave filled with air-free H
a water bath, the temperature of which was adjusted to the
0 °C. H pressure was adjusted to 1 MPa, then reacted for
2
gas was put in
2
3
2