Enantioselective epoxidation with peroxidic oxygen
1993; Springer Science+Business Media; Linguagem: Inglês
10.1007/3-540-56252-4_25
ISSN1436-5049
Autores Tópico(s)Chemical Synthesis and Reactions
ResumoOptically active epoxides are versatile and important intermediates for the preparation of homochiral oxygen-containing compounds. The main route to such optically active epoxides is the enantioselective epoxidation of olefins by reagents containing peroxidic oxygen. Besides the application of optically active oxidizing agents, hydrogen peroxide in the presence of optical auxiliaries, and molybdenum peroxo complexes with chiral ligands, the Sharpless epoxidation of allylic alcohols using t-butyl hydroperoxide in the presence of titanium isopropoxide and l-(+)- or d-(−)-dialkyl tartrate ester is the most practicable method for the preparation of homochiral epoxy alcohols. This development is reviewed briefly followed by own results concerning the Sharpless epoxidation of C5-allylic alcohols and the use of various hydroperoxides in this reaction. It is known that racemic allylic alcohols can be kinetically resolved by the asymmetric epoxidation procedure. Now preliminary results can be presented regarding the kinetic resolution of racemic hydroperoxides via Sharpless epoxidation and a new method for determining of the ratio of enantiomers in chiral hydroperoxides by HPLC is described.
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