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Synlett 2002(10): 1739-1740
DOI: 10.1055/s-2002-34238
SPOTLIGHT
© Georg Thieme Verlag Stuttgart · New York

Barium Hydroxide Ba(OH)2·8H2O

Stephane Jeanmart*
a Laboratoire de Chimie Organique de Synthèse, 61 rue deBruxelles, 5000 Namur, Belgium
b Fonds pour la formation à la Recherche dans l’Industrie et l’Agriculture (F.R.I.A.), 5 rue d’Egmont, 1000 Bruxelles, Belgium
e-Mail: Stephane.jeanmart@fundp.ac.be;
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Publikationsdatum:
23. September 2002 (online)

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Introduction

Barium hydroxide is a highly valuable reagent, in organic synthesis, due to the availability of the hydroxide ion in solution, the size of the barium counter ion, and for some of its forms, its microcrystalline structure [1] when it is insoluble or partly insoluble in the medium. Ba(OH)2·8H2O is the most common form and is commercially available. [2] Activated barium hydroxide Ba(OH)2 (C-200), [Ba(OH)2·H2O] is obtained by heating commercial Ba(OH)2·8H2O in an oven at 200 °C for 3 h and powdering the resulting product. [3] Barium hydroxide reacts as a base [4-7] or as a nucleophile, [8] [9] in homogenous [9] [10] or heterogeneous conditions. [1] [4] [7] [11] Barium hydroxide was revealed to be efficient in deacylations, [12] in Michael addition, [3] in aldol or aldol-type condensation, [13] in Wittig-Horner reactions, [11] [14] [15] in Claisen-Schmidt reactions, [16] in Canizzaro reactions, [6] and in Suzuki coupling. [5] [10] [17]