Lithium perchlorate catalyzed acetylation of alcohols under mild reaction conditions

Article abstract of DOI:10.1055/s-2001-17483

Lithium perchlorate is found to efficiently catalyze the acetylation of alcohols and phenols with acetic anhydride in good to excellent yields.

Full text of DOI:10.1055/s-2001-17483

1584
LETTER
Lithium Perchlorate Catalyzed Acetylation of Alcohols under Mild Reaction
Conditions
L
ithium Perchlorat
a
e
C
atalyzed
s
Acetyla
t
u
ion of Alcoh
y
ols uki Nakae, Ikuko Kusaki, Tsuneo Sato*
Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, Kurashiki 712-8505, Japan
Fax +81(86)4401062; E-mail: sato@chem.kusa.ac.jp
Received 26 July 2001
ically hindered secondary alcohols afforded the acetates
Abstract: Lithium perchlorate is found to efficiently catalyze the
acetylation of alcohols and phenols with acetic anhydride in good to
excellent yields.
in excellent yields (entries 8 and 9). Neither racemization
nor epimerization was observed at all under the reaction
conditions (entries 10 and 11). Exposure of a disulfide-
containing diol to LiClO4/Ac2O furnished the correspond-
ing diacetate in quantitative yield (entry 5). On the other
hand, the same substrate was treated with PBu3 or
Sc(OTf)3 in the presence of Ac2O, the disulfide bond un-
derwent cleavage to give AcOCH2CH2SAc.19
Key words: acetylation, acylation, alcohols, Lewis acids, lithium
perchlorate
The acetylation of alcohols is one of the most basic trans-
formations in organic synthesis.1 It is generally carried out
by using acetic anhydride or acetyl chloride in the pres-
ence of tertiary amines such as triethylamine or pyridine.
4-(Dimethylamino)pyridine (DMAP) is known to in-
crease the rate of acetylation when used as a co-catalyst.2
Tributylphosphine has been introduced as a less basic cat-
Interestingly, hindered tertiary alcohols such as 1-ada-
mantanol, 1-ethynylcyclohexanol, and 2-methyl-2-unde-
canol were also cleanly and efficiently acetylated at
ambient temperatures (entries 12–14). It is noteworthy
that a tertiary aldol can be acetylated in 90% yield under
such reaction conditions without significant formation of
alyst for the acetylation of alcohols.3 In addition to the
4–11
a
, -unsaturated carbonyl compound, which was ob-
above catalysts, protic or Lewis acids,
or sometimes
solid acid catalysts12–14 are also known to catalyze the acy-
lation of alcohols with acid anhydrides. Recently, scandi-
um trifluoromethanesulfonate has been used as an
efficient catalyst for the acetylation of alcohols.15 Most re-
cently, the use of bismuth trifluoromethanesulfonate as a
milder acylation catalyst than Sc(OTf)3 has been report-
ed.16 Even though a great number of catalysts have been
reported for this transformation, there is still a great de-
mand for mild Lewis acid catalysts to generate esters.
Lithium perchlorate has been used as a mild and efficient
Lewis acid catalyst for a number of organic reactions.17 In
this paper we wish to disclose a new method for the acety-
lation of alcohols using acetic anhydride in the presence
of a catalytic amount of LiClO4 (10 mol%) under solvent-
free conditions (Scheme).18
tained in substantial amounts when acetylation was car-
ried out by the conventional DMAP/Ac2O method (entry
15).20
In order to extend the scope of the catalyst further, the
acetylation of phenols was investigated (entries 16 and
17), and it was found that a hindered phenol is acylated in
good yield (entry 16).
In conclusion, we have shown that lithium perchlorate is
a very efficient and versatile catalyst for acylation of alco-
hols and phenols. The advantage of the method is that
even hindered substrates can be acylated in high yield un-
der mild reaction conditions. Works on other reactions
catalyzed by lithium perchlorate are currently underway
in our laboratory.
Table Acetylation of Alcohols Catalyzed by LiClO4
LiClO4 (10 mol%)
+
R
OH
Ac2O
R OAc
Entry Alcohol
Ac2O
(equiv) (°C)
Temp Time Yielda
(h)
(%)
Scheme
1
2
3
geraniol
nerol
2
2
2
25
25
25
9
84
As shown in the Table, a series of alcohols and phenols
was acetylated with acetic anhydride under catalysis by
LiClO4. Primary and secondary alcohols both in allylic
and propargylic underwent smooth acetylation without
any trace of by-products arising from rearrangement (en-
tries 1–3, 6–7). Acid-sensitive furfuryl alcohol was also
acetylated in quantitative yield (entry 4). Further, the ster-
9
83
9
89
OH
4
2
25
9
100
OH
O
Synlett 2001, No. 10, 28 09 2001. Article Identifier:
1437-2096,E;2001,0,10,1584,1586,ftx,en;Y14801st.pdf.
© Georg Thieme Verlag Stuttgart · New York
ISSN 0936-5214

LETTER
Lithium Perchlorate Catalyzed Acetylation of Alcohols
1585
Table Acetylation of Alcohols Catalyzed by LiClO4 (continued)
References and Notes
(1) (a) Reese, C. B. Protective Groups in Organic Chemistry;
McOmie, J. F. W., Ed.; Plenum: London, 1973, 109.
(b) Kocienski, P. J. Protecting Groups; Thieme: New York,
1994, 22. (c) Greene, T. W.; Wuts, P. G. M. Protective
Groups in Organic Synthesis, 3rd ed.; Wiley: New York,
1999, 150. (d) Larock, R. C. Comprehensive Organic
Transformations, 2nd ed.; Wiley-VCH: New York, 1999,
1955.
(2) (a) Höfle, G.; Steglich, W.; Vorbrüggen, H .Angew. Chem.
Int. Ed. Engl. 1978, 17, 569. (b) Scriven, E. F. V. Chem.
Soc. Rev. 1983, 12, 129.
(3) (a) Vedejs, E.; Diver, S. T. J. Am. Chem. Soc. 1993, 115,
3358. (b) Vedejs, E.; Bennett, N. S.; Conn, L. M.; Diver, S.
T.; Gingras, M.; Lin, S.; Oliver, P. A.; Peterson, M. J. J. Org.
Chem. 1993, 58, 7286.
Entry Alcohol
Ac2O
(equiv) (°C)
Temp Time Yielda
(h)
(%)
5
4
25
25
(100)b
S(CH2)2OH
S(CH2)2OH
2
25
22
6
100
100
OH
6
7
Ph
2
25
OH
n-C5H11
(4) p-Toluenesulfonic acid: (a) Turner, R. B. J. Am. Chem. Soc.
1953, 75, 3489. (b) Cope, A. C.; Herrick, E. C. Org. Synth.
1963, 4, 304.
8
9
menthol
2
2
2
25
25
40
22
6
(98)
(98)
(85)
borneol
(5) (a) Sulfamic acid: Jin, T.-S.; Ma, Y.-R.; Zhang, Z.-H.; Li, T.-
S. Synth. Commun. 1998, 28, 3173. (b) LiCl: Sabitha, G.;
Reddy, B. V. S.; Srividya, R.; Yadav, J. S. Synth. Commun.
1999, 29, 2311. (c) BF3·OEt2: Nagao, Y.; Fujita, E.; Kohno,
T.; Yagi, M. Chem. Pharm. Bull. 1981, 29, 3202.
(d) MgBr2: Pansare, S. V.; Malusare, M. G.; Rai, A. N.
Synth. Commun. 2000, 30, 2587. (e) MgBr2-R3N: Vedejs,
E.; Daugulis, O. J. Org. Chem. 1996, 61, 5702.
(6) TMSCl: (a) Barua, N. C.; Sharma, R. P.; Baruah, J. N.
Tetrahedron Lett. 1983, 24, 1189. (b) Matteson, D. S.;
Beedle, E. C.; Kandil, A. A. J. Org. Chem. 1987, 52, 5034.
(c) Kumareswaran, R.; Gupta, A.; Vankar, Y. D. Synth.
Commun. 1997, 27, 277.
10
48
OH
COOEt
OH
11
12
2
40
25
4
(92)
(95)
CONMe2
Ph
10
21
OH
(7) TMSOTf: (a) Procopiou, P. A.; Baugh, S. P. D.; Flack, S. S.;
Inglis, G. G. A. Chem. Commun. 1996, 2625.
(b) Procopiou, P. A.; Baugh, S. P. D.; Flack, S. S.; Inglis, G.
G. A. J. Org. Chem. 1998, 63, 2342.
(8) (a) P(MeNCH2CH2)3N: D’Sa, B. A.; Verkade, J. G. J. Org.
Chem. 1996, 61, 2963. (b) Sc(NTf2)3: Ishihara, K.; Kubota,
M.; Yamamoto, H. Synlett 1996, 265. (c)
13
14
10
10
25
25
48
24
(89)
OH
Sc[C(SO2C8F17)3]3: Mikami, K.; Mikami, Y.; Matsumoto,
Y.; Nishikido, J.; Yamamoto, F.; Nakajima, H. Tetrahedron
Lett. 2001, 42, 289. (d) FeCl3: Sharma, G. V. M.;
Mahalingam, A. K.; Nagarajan, M.; Ilangovan, A.;
Radhakrishna, P. Synlett 1999, 1200. (e) CoCl2: see
reference 20. (f) Cu(OTf)2: Saravanan, P.; Singh, V. K.
Tetrahedron Lett. 1999, 40, 2611.
(93)c
OH
n-C9H19
15
16
10
2
40
40
18
18
(90)c
(91)
OH
O
(9) ZnCl2: (a) Baker, R. H.; Bordwell, F. G. Org. Synth. 1955, 3,
141. (b) Holton, R. A.; Zhang, Z.; Clarke, P. A.; Nadizadeh,
H.; Procter, D. J. Tetrahedron Lett. 1998, 39, 2883.
(10) (a) NBS: Karimi, B.; Seradj, H. Synlett 2001, 519. (b)
In(OTf)3: Chauhan, K. K.; Frost, C. G.; Love, I.; Waite, D.
Synlett 1999, 1743. (c) Distannoxane: Orita, A.; Ito, T.;
Yasui, Y.; Otera, J. Synlett 1999, 1927. (d)
OH
R2Sn(OH)22+(OTf)– : Skamoto, K.; Hamada, Y.; Akashi, H.;
2
Orita, A.; Otera, J. Organometallics 1999, 18, 3555. (e)
CeCl3: Damen, E. W. P.; Braamer, L.; Scheeren, H. W.
Tetrahedron Lett. 1998, 39, 6081. (f)
17
phenol
2
40
6
(90)
Sm{[N(SO2OCH(CF3)2]2}3: Nie, J.; Zhao, Z.; Xu, J.; Liu, D.
J. Chem. Res. (S) 1999, 160.
(11) I2: (a) Kartha, K. P. R.; Field, R. A. Tetrahedron 1997, 53,
11753. (b) Borah, R.; Deka, N.; Sarma, J. C. J. Chem. Res.
(S) 1997, 110.
a Based on GC. Isolated yields are given in the parentheses.
b Yield refers to pure diacetate.
c Trace amounts of olefin(s) (ca. 1% checked by GC) were detected.
Synlett 2001, No. 10, 1584–1586 ISSN 0936-5214 © Thieme Stuttgart · New York

1586
Y. Nakae et al.
LETTER
(16) Orita, A.; Tanahashi, C.; Kakuda, A.; Otera, J. Angew.
(12) (a) Amberlyst-15: Srivastava, V.; Tandon, A.; Ray, S.
Synth. Commun. 1992, 22, 2703. (b) Expansive graphite:
Jin, T.-S.; Ma, Y.-R.; Li, T.-S.; Zhang, Z.-H.; Duan, G.-B.
Indian J. Chem. 1999, 38B, 109. (c) Graphite bisulfate:
Secen, H.; Kalpar, A. H. Turk. J. Chem. 1999, 23, 27. (d)
HZSM-5-zeolite: Heravi, M. M.; Tajbakhsh, M.;
Mohajerani, B.; Ghassemzadeh, M. Indian J. Chem. 1999,
38B, 859.
(13) Montmorillonite K-10 and KSF: (a) Li, A.-X.; Li, T.-S.;
Ding, T.-H. Chem. Commun. 1997, 1389. (b) Li, T.-S.; Li,
A.-X. J. Chem. Soc. Perkin Trans. 1 1998, 1913.
(c) Bhaskar, P. M.; Loganathan, D. Tetrahedron Lett. 1998,
39, 2215.
(14) (a) Nafion-H: Kumareswaran, R.; Pachamuthu, K.; Vankar,
Y. D. Synlett 2000, 1652. (b) TaCl5-SiO2: Chandrasekhar,
S.; Ramachander, T.; Takhi, M. Tetrahedron Lett. 1998, 39,
3263. (c) Yttria-zirconia: Kumar, P.; Pandey, R. K.; Bodas,
M. S.; Dongare, M. K. Synlett 2001, 206. (d) Zeolite HSZ-
360: Ballini, R.; Bosica, G.; Carloni, S.; Ciaralli, L.; Maggi,
R.; Sartori, G. Tetrahedron Lett. 1998, 39, 6049. (e)
Zirconium sulfophenyl phosphonate: Curini, M.; Epifano,
F.; Marcotullio, M. C.; Rosati, O.; Rossi, M. Synth.
Commun. 2000, 30, 1319.
Chem. Int. Ed. 2000, 39, 2877.
(17) (a) Grieco, P. A. Aldrichimica Acta 1991, 24, 59.
(b) Waldmann, H. Angew. Chem. Int. Ed. Engl. 1991, 30,
1306. (c) Flohr, A.; Waldmann, H. J. Prakt. Chem. 1995,
337, 609. (d) Sankararaman, S.; Nesakumar, J. E. Eur. J.
Org. Chem. 2000, 2003. (e) Saito, N.; Grieco, P. A. J. Synth.
Org. Chem. Jpn. 2000, 58, 39. (f) Saito, S. Lewis Acids in
Organic Synthesis, Vol. 1; Yamamoto, H., Ed.; Wiley-VCH:
New York, 2000, 9.
(18) General experimental procedure for acetylation of alcohols
using Ac2O and LiClO4: A mixture of alcohol (2 mmol),
Ac2O (4-20 mmol), and LiClO4 (0.2 mmol) was stirred at the
temperature indicated in the Table. The progress of the
reaction was followed by TLC or GC. After completion, the
reaction was quenched with water (20 cm3). The resulting
mixture was extracted with ethyl acetate (2 30 cm3). The
organic layer was successively washed with saturated
NaHCO3 solution (2 20 cm3) and with brine (20 cm3), and
dried (Na2SO4). Evaporation gave the almost pure acetate.
Further purification was achieved by column chromato-
graphy on silica gel (ethyl acetate–hexane) to afford pure
acetate.
(15) (a) Ishihara, K.; Kubota, M.; Kurihara, H.; Yamamoto, H. J.
Am. Chem. Soc. 1995, 117, 4413. (b) Ishihara, K.; Kubota,
M.; Kurihara, H.; Yamamoto, H. J. Org. Chem. 1996, 61,
4560. (c) Roush, W. R.; Barda, D. A. Tetrahedron Lett.
1997, 38, 8785. (d) Orita, A.; Nagano, Y.; Nakazawa, K.;
Otera, J. Synlett 2000, 599.
(19) Orita, A.; Mitsutome, A.; Otera, J. J. Org. Chem. 1998, 63,
2420.
(20) (a) Ahmad, S.; Iqbal, J. J. Chem. Soc., Chem. Commun.
1987, 114. (b) Iqbal, J.; Srivastava, R. R. J. Org. Chem.
1992, 57, 2001.
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