Monatsh Chem (2009) 140:1485–1488
DOI 10.1007/s00706-009-0212-9
ORIGINAL PAPER
1,3-Dibromo-5,5-dimethylhydantoin or N-bromosuccinimide
as efficient reagents for chemoselective deprotection
of 1,1-diacetates under solvent-free conditions
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Behrooz Maleki Davood Azarifar Ramin Ghorbani-vaghei
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Hojat Veisi Seyedeh Fatemeh Hojati Mostafa Gholizadeh Hafezeh Salehabadi
Mona Khodaverdian Moghadam
Received: 23 February 2009 / Accepted: 13 October 2009 / Published online: 7 November 2009
Ó Springer-Verlag 2009
Abstract A simple and efficient method is reported for
rapid chemoselective transformation of 1,1-diacetates to
the parent aldehydes using 1,3-dibromo-5,5-dimethylhy-
dantoin or N-bromosuccinimide in the presence of wet
SiO2 (50%, w/w) as solid support under solvent-free con-
ditions at room temperature. This procedure has valuable
advantages, for example short reaction times, simple work-
up, high yields of products, absence of solvent, and use of
commercially available and non-toxic reagents.
chemistry [1, 2]. Among the different functional groups,
carbonyl groups have attracted special attention in protec-
tion and deprotection reactions by virtue of their high
reactivity. One useful practice for protection of carbonyl
groups is 1,1-diacetylization, which has received consid-
erable interest in recent years, because 1,1-diacetates are
stable in mildly acidic and basic media and are easily pre-
pared [3–10]. However, the search for appropriate
and efficient methods for deprotection of 1,1-diacetates to
the corresponding carbonyl compounds is still in high
demand. In this regard, much effort has been devoted
to developing numerous methodologies using various
reagents such as phosphorus trichloride [11], boron triio-
dide–N,N-diethylaniline complex [12], mineral solid
supports [13], MoO2(acac)2 [14], FeCl3Á6H2O [15],
graphite [16], CuCl2Á2H2O [17], zirconium sulfophenyl
phosphonate [18], ceric ammonium nitrate (CAN) [19],
indium trichloride [20], [NO?. crown. H (NO3)2-]
[21], Caro’s acid/SiO2 [22], H6P2W18O62Á24H2O [23],
Fe2(SO4)3ÁxH2O [24], 12-molybdophoshoric acid [25],
p-toluene sulfonic acid [26], SO42-/SnO2 [27], molybde-
num tungsten polyoxometalates [28], KBrO3/MoO3
[29], (NH4)3PW12O40 [30], dodecatungstophosphoric acid
(H3PW12O40) [31], sodium hydrogen sulfate in poly(eth-
ylene glycol) [32], indium tribromide/[bmim]PF6 [33],
indium tribromide in poly(ethylene glycol) [34], 2,6-dica-
rboxypyridinium chlorochromate [35], and ZrOCl2 [36].
Although many of these procedures have been satisfactorily
used for this propose, most suffer from one or more draw-
backs, for example low yields, harsh reaction conditions,
difficult work-up, and use of expensive and/or toxic
reagents and solvents. In view of these limitations and also
with regard to yields, reaction time, toxicity, and catalytic
loading, our method is believed to be superior to those
previously reported.
Keywords 1,1-Diacetates Á Aldehydes Á Wet silica gel Á
1,3-Dibromo-5,5-dimethylhydantoin Á
N-Bromosuccinimide Á Solvent-free conditions
Introduction
Protection and deprotection of functional groups are
important and extensively used transformations in synthetic
B. Maleki (&) Á S. F. Hojati Á M. Gholizadeh Á
H. Salehabadi Á M. K. Moghadam
Department of Chemistry,
Sabzevar Tarbiat Moallem University,
Sabzevar, Iran
e-mail: malekibehrooz@gmail.com
D. Azarifar Á R. Ghorbani-vaghei
Department of Chemistry,
Bu-Ali Sina University,
Hamadan, Iran
H. Veisi
Department of Chemistry,
Payame Noor University, Songhor,
Kermanshah, Iran
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