ORGANIC
LETTERS
1999
Vol. 1, No. 11
1701-1703
A Mild, Efficient, Inexpensive, and
Selective Cleavage of Primary
tert-Butyldimethylsilyl Ethers by Oxone
in Aqueous Methanol†
Gowravaram Sabitha,* Mandali Syamala, and J. S.Yadav
Indian Institute of Chemical Technology, Hyderabad 500 007, India
Received June 22, 1999
ABSTRACT
The use of a 50% aqueous methonolic solution of Oxone is described for the selective cleavage of primary tert-butyldimethylsilyl and aryl
ethers at room temperature. This method enables one to deprotect tert-butyldimethylsilyl ethers of primary alcohols in the presence of tert-
butyldimethylsilyl ethers of secondary and tertiary alcohols and phenols. The silyl ethers of phenols were deprotected at longer reaction
times.
The tert-butyldimethylsilyl (TBDMS)1 group is one of the
most frequently used protecting groups for the hydroxyl
function in organic synthesis. This is due to easy installa-
tion1,2 and general stability to basic and mildly acidic
reagents.1 Even though a variety of reagents3-11 have been
developed for the cleavage of TBDMS ethers, most of these
methods suffer from the use of basic3 or strong oxidizing7,8
and reducing6 reagents and cumbersome workup. Herein we
report a new method for the selective cleavage of primary
TBDMS ethers by Oxone (KHSO5 triple salt)12 under mild
conditions which can tolerate a wide variety of other
functional groups (Table 1).
Literature shows a number of methods available for the
cleavage of alkylsilyl ethers, but there are only a few methods
reported13 for the cleavage of phenolic TBDMS ethers. Most
of these methods use basic reagents and required elevated
temperatures. Therefore, there still exists a great demand for
a mild reagent which works for the cleavage of alkyl as well
as phenolic TBDMS ethers with selectivity among these two
groups, because the selectivity can be applied to advantage
in complex synthetic sequences in which two protected
hydroxyl groups must be unmasked at different stages of
the synthesis.
†IICT Communication No. 4340.
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10.1021/ol990140h CCC: $18.00 © 1999 American Chemical Society
Published on Web 10/29/1999