710
M. A. Chari, K. Syamasundar
SHORT PAPER
Table 1 Polymer-Supported FeCl3-Catalyzed Acetonide Deprotection (continued)
Entry
n
Substrate (1)
Product (2)
Time (min)
30
Yield (%)
94
o
25
94
3-O-(tert-Butyldimethylsiyl)-1,2-O-isopropylidene-a-D-gluco-
In conclusion, we have developed a simple, convenient
and effective method for the synthesis of 1,2-diols, which
has the advantages of mild reaction conditions, high
chemoselectivity, reduced reaction time, inexpensive cat-
alyst, high yields of products and simple experimental
work-up procedure. Polymer (PVP)-supported, ferric
chloride-catalyzed acetonide deprotection has been devel-
oped to produce 1,2-diols, which will be an important ad-
dition to the present existing procedures. To our
knowledge, this is first time report of an efficient general
furanose (2j)
IR: 1250 cm–1.
1H NMR (CDCl3, 200 MHz): d = 0.16 (s, 6 H), 0.83 (s, 9 H), 1.32
(s, 3 H), 1.50 (s, 3 H), 2.0 (br s, 1 H), 2.51 (br s, 1 H), 3.75–4.40 (m,
6 H), 5.93 (d, J = 3.7 Hz, 1 H).
13C NMR (CDCl3, 50 MHz): d = –5.14, –4.86, 17.94, 25.63, 26.23,
64.43, 68.71, 75.72, 80.85, 85.28, 104.93, 111.74.
MS (FAB): m/z = 318 (M + 1).
Anal. Calcd for C15H30O6Si : C, 53.86; H, 9.04. Found: C, 53.80; H,
method for the synthesis of 1,2-diols by using a simple 8.97.
catalyst.
References
(1) (a) Green, T. W.; Wuts, P. G. M. Protective Groups in
Organic Synthesis, 2nd ed.; Wiley: New York, 1991.
(b) Kocienski, P. J. Protective Groups; Thieme: Stuttgart,
New York, 1994.
(2) Hanessian, S. Total Synthesis of Natural Products: The
Chiron Approach; Pergamon: Oxford, 1984.
(3) Fleet, G. W. J.; Smith, P. W. Tetrahedron Lett. 1985, 26,
1469.
(4) Gerspacher, M.; Rapoport, H. J. Org. Chem. 1991, 56, 3700.
(5) Yadav, J. S.; Chander, M. C.; Reddy, K. K. Tetrahedron
Lett. 1992, 33, 135.
(6) Sukumar, M.; Jacques, V.; Pendri, Y.; Falck, J. R.
Tetrahedron Lett. 1986, 27, 2679.
(7) Iwata, M.; Ohrui, H. Bull. Chem. Soc. Jpn. 1981, 54, 2937.
(8) Vijayasaradhi, S.; Singh, J.; Aidhen, I. S. Synlett 2000, 110.
(9) Xiao, X.; Bai, D. Synlett 2001, 535.
(10) Venkateswarlu, Y.; Raghavendraswamy, N. Tetrahedron
Lett. 2002, 27, 7549.
(11) Clark, J. H. In Catalysis of Organic Reactions Supported by
Inorganic Reactions; VCH: New York, 1994.
(12) (a) Caddick, S. Tetrahedron 1995, 51, 10403. (b) Boruah,
A.; Baruah, B.; Prajapathi, D.; Sandhu, J. Tetrahedron Lett.
1997, 38, 4267. (c) Bose, D. S.; Jayalakshmi, B. J. Org.
Chem. 1999, 64, 1713.
1,2-Diols from Acetonides; General Procedure
A solution of the acetonide (1 mmol) in MeCN (10 mL) was treated
with polymer supported FeCl3 (5 mol%) and H2O (2 drops) and
stirred for an appropriate time (Table 1) at r.t. After completion of
the reaction, NaHCO3 was added and solvent was removed under
reduced pressure, H2O was added the mixture extracted into EtOAc,
washed with brine, dried (Na2SO4) and concentrated to give the
crude product, which was purified (silica gel column) to provide the
pure 1,2-diols in high yields.
Catalyst Preparation
Powdered poly(4-vinylpyridine) (1 g) was dissolved in a standard
solution of FeCl3 in H2O (0.1 M, 10 mL). FeCl3 (1 mmol, 161 mg)
was added. After the solution had been stirred for 30 min at 30 °C,
the solid PVP–Fe(III) was filtered off. The excessive ferric ions in
the complex were washed off with deionized H2O. The solid pow-
der was dried under vacuum at 65 °C for 24 h. The absorbed
amounts of the ferric ions in the complex were obtained using UV
spectrophotometry. The catalyst was washed with solvents and
dried then reused for subsequent reactions. In the polymer-support-
ed FeCl3, the polymer strongly binds to the catalyst, so the catalyst
can be recovered without loss of any FeCl3.
Spectral Data for Selected Compounds
(13) Varma, R. S.; Dahiya, R.; Saini, R. K. Tetrahedron Lett.
3-O-Tetrahydropyranyl-1,2-isopropylidene-a-D-glucofuranose
1997, 38, 7029.
(2i)
(14) (a) Bose, D. S.; Vanajatha, G.; Srinivas, P. Indian J. Chem.,
Sect. B: Org. Chem. Incl. Med. Chem. 1999, 38, 835.
(b) Bose, D. S.; Raveender Goud, P. Tetrahedron Lett. 1999,
40, 747.
(15) Wu, K. H.; Wang, Y. R.; Hwu, W. H. Polym. Degrad. Stab.
2003, 79, 195.
1H NMR (CDCl3, 200 MHz): d = 1.35 (s, 3 H), 1.48 (s, 3 H), 1.54–
1.62 (m, 2 H), 1.77–1.90 (m, 2 H), 3.47–3.62 (m, 2 H), 3.64–3.79
(m, 2 H), 3.73–3.81 (m, 1 H), 4.01 (m, 3 H), 4.22–4.32 (m, 1 H),
4.0–4.51 (m, 1 H), 4.6–4.69 (m, 1 H), 5.91 (d, J = 7.5 Hz, 1 H).
Synthesis 2005, No. 5, 708–710 © Thieme Stuttgart · New York