Synthesis 2009(20): 3433-3438  
DOI: 10.1055/s-0029-1216956
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Erbium(III) Triflate is a Highly Efficient Catalyst for the Synthesis of β-Alkoxy Alcohols, 1,2-Diols and β-Hydroxy Sulfides by Ring Opening of Epoxides

Renato Dalpozzoa, Monica Nardi*a, Manuela Oliveriob, Rosina Paonessab, Antonio Procopiob
a Dipartimento di Chimica, Università della Calabria, ponte Bucci cubo 12/c, 87030 Arcavacata di Rende (Cs), Italy, Fax: +39(0984)493077; e-Mail: nardi@unical.it;
b Dipartimento Farmacobiologico, Università della Magna Graecia, Complesso Ninì Barbieri, 88021 Roccelletta Di Borgia (CZ), Italy
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Publikationsverlauf

Received 25 May 2009
Publikationsdatum:
21. August 2009 (online)

Abstract

Chemo- and stereoselectivity in the ring-opening reaction of epoxides with erbium(III) triflate are described. Epoxides can be cleaved under neutral conditions with alcohols and thiols in the presence of catalytic amounts of Lewis acid, affording the corresponding β-alkoxy alcohols and β-hydroxy sulfides in high yields. In water, epoxide ring opening occurs to produce the corresponding diols in good yields

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A 0.1 M aqueous solution of Er(OTf)3 is only weakly acidic (pH ca. 5.9), and the aqueous layer from workup is even less acidic (pH ca. 6.6).