LETTER
An Efficient Catalyst for the Direct Conversion of Primary and Secondary Trimethylsilyl Ethers
1879
References
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(
(
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chemicals companies. The products were characterized by
(
1
comparison of their spectral (IR, H NMR), TLC and
(
(
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1
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10a
procedure. All silyl ethers were synthesized according to
(
(
(
13
the reported procedure.
1
(
12) Preparation of Silica Sulfuric Acid: A 500 mL suction
flask was used. It was equipped with a constant-pressure
dropping funnel containing chlorosulfonic acid (23.3 g, 0.2
mol) and gas inlet tube for conducting HCl gas over an
adsorbing solution i. e. H O. Into it were charged 60.0 g of
2
silica gel. Chlorosulfonic acid was added dropwise over a
period of 30 min at r.t. HCl gas evolved from the reaction
vessel immediately. After the addition was complete the
mixture was shaken for 30 min. A white solid (silica sulfuric
(
10) (a) Zolfigol, M. A. Tetrahedron 2001, 57, 9509.
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(
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Bamoniri, A. Molecules 2002, 7, 751. (e) Zolfigol, M. A.;
Ghaemi, E.; Madrakian, E. Molecules 2002, 7, 734.
10a
acid) 76.0 g was obtained.
(
(
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(
f) Zolfigol, M. A.; Shirini, F.; Ghorbani-Choghamarani, A.;
Synlett 2003, No. 12, 1877–1879 © Thieme Stuttgart · New York