M. Kirihara et al. / Tetrahedron Letters 51 (2010) 3619–3622
3621
Table 3 (continued)
Entry
Diol
Ketone
Time (h)
Yielda (%)
40c
Me
Me
O
OH
Me
OH
8
0.5
Me
Complex mix.b
7
8
Me
O
O
OH
OH
Me
Me
8
0.5
60d
Complex mix.b
Me
O
a
Isolated yields.
Reaction in refluxing AcOEt.
2-Methyl-1-methyleneindan-2-ol (24%) was obtained as a byproduct.
2-Methyl-1-methyleneindan-2-ol (20%) was obtained as a byproduct.
b
c
d
Table 4
2.4 mol% VOCl3,
O2 (balloon)
No Reaction
OH
2.4 mol% VOCl3,
O2 (balloon)
AcOEt, rt or
EtOH, reflux
HO OH
R1
R2
H
R4
AcOEt, rt or
EtOH, reflux
Scheme 3.
Entry
1
Diol
Solvent
Product
cleavage of ditertiary glycols. Further study of the mechanism is
currently underway.
A typical experimental procedure is as follows: a mixture con-
taining the ditertiary glycol (5.0 mmol), VOCl3 (11.3 ll,
HO OH
Bu
Ph
O
H
quant.*
AcOEt
Ph
Bu
Ph
0.12 mmol), and ethyl acetate (50 ml) is stirred at room tempera-
ture under an oxygen atmosphere. The reaction is monitored by
thin layer chromatography (TLC). After the ditertiary glycol disap-
pears from the TLC, the reaction is quenched with saturated aque-
ous sodium bicarbonate and the reaction mixture is extracted with
20 ml ꢀ 3 of ethyl acetate. The combined organic extract is washed
with brine, dried over anhydrous magnesium sulfate, and evapo-
rated. Chromatography on silica gel gives the product.
+ complex mixture
O
HO OH
H
Bu
Ph
quant.*
2
EtOH
Ph
Bu
Ph
+ complex mixture
Ph OH
OH
H
3
4
AcOEt
AcOEt
Complex mixture
References and notes
Ph OH
H
OH
Complex mixture
1. Reviews: Perlin, A. S. Adv. Carbohydr. Chem. Biochem. 2006, 60, 183–250; Shing,
T. K. M.. In Comprehensive Organic Synthesis; Trost, B. M., Ed.; Pergamon Press:
Oxford, 1991; Vol. 7, pp 703–716.
*Based on GC analysis.
2. Representative papers of glycol cleavage except for periodates and lead
tetraacetate: Pausacker, K. H. J. Chem. Soc. 1953, 107–109; Barton, D. H. R.;
Kitchin, J. P.; Lester, D. J.; Motherwell, W. B.; Pichon, C. Tetrahedron 1981, 37, 73–
79; Rao, S. P.; Gaur, J. N.; Sharma, S. K. Naurwissenshaften 1961, 48, 98;
Nwaukwa, S. O.; Keehn, P. M. Tetrahedron Lett. 1982, 23, 3135–3138; Cisneros,
A.; Fernandez, S.; Hernandez, J. E. Synth. Commun. 1982, 12, 833–838; Verturello,
C.; Ricci, M. J. Org. Chem. 1986, 51, 1599–1602; Ohloff, G.; Giersch, W. Angew.
Chem., Int. Ed. Engl. 1973, 12, 401–402.
3. Reviews: Rezaeivalla, M. Synlett 2006, 3550–3551; Faitadi, A. J. Synthesis 1974,
220–272.
4. Reviews: Mihailovic, M. L.; Cekovic, Z.; Mathes, B. M. e-EROS Encyclopedia of
Reagents for Organic Synthesis 2001, No pp. given.; Mihailovic, M. L.; Cekovic, Z.;
Lorenc, L. Org. Synth. Oxid. Met. Compd. 1986, 741–816.
Although the reaction also proceeded for secondary–tertiary
glycols, complex mixtures were obtained (Table 4). In the case of
an acyclic diol (run 1), the corresponding ketone (butyl phenyl ke-
tone) was quantitatively obtained, as part of a complex mixture.
This result indicates that the tertiary alcohol portion of the reac-
tant affords the ketone, and the secondary alcohol fragment yields
complex mixtures.
This VOCl3-catalyzed aerobic cleavage of a ditertiary glycol is
highly chemoselective, as we previously reported.5 Furthermore,
an allyl alcohol (geraniol) was completely inert in the presence
of a catalytic amount of VOCl3 under an oxygen atmosphere and
was quantitatively recovered (Scheme 3). This phenomenon is in
sharp contrast to the VO(acac)2-catalyzed oxidation in the pres-
ence of t-butyl hydroperoxide which produces epoxides.
In conclusion, this VOCl3-catalyzed aerobic oxidation provides a
pathway to the environmentally benign carbon–carbon bonds
5. Kirihara, M.; Takizawa, S.; Momose, T. J. Chem. Soc., Perkin Trans. 1 1998, 7–8.
6. Kirihara, M.; Ochiai, Y.; Takizawa, S.; Takahata, H.; Nemoto, H. Chem. Commun.
1999, 1387–1388.
7. Representative papers of aerobic oxidation reactions catalyzed by vanadium
compounds: Kikushima, K.; Moriuchi, T.; Hirao, T. Tetrahedron Lett. 2010, 51,
340–342; Takizawa, S. Chem. Pharm. Bull. 2009, 57, 1179–1188; Moriuchi, T.;
Kikushima, K.; Kajikawa, T.; Hirao, T. Tetrahedron Lett. 2009, 50, 7385–7387;
Kikushima, K.; Moriuchi, T.; Hirao, T. Chem. Asian J. 2009, 4, 1213–1216; Singhal,
S.; Jain, S.; Sain, B. Chem. Commun. 2009, 2371–2372; Takizawa, S.; Katayama, T.;
Sasai, H. Chem. Commun. 2008, 4113–4122; Takizawa, S.; Katayama, T.;
Kameyama, C.; Onitska, K.; Suzuki, T.; Yanagida, T.; Kawai, T.; Sasai, H. Chem.
Commun. 2008, 1810–1812; Takizawa, S.; Katayama, T.; Somei, H.; Asano, Y.;