Oxiranes synthesis from halohydrins

Finally, mention may be made of those articles in which this method is utilized in the synthesis of optically active oxiranes for example, the simple synthesis of monosubstituted (S)-oxiranes and the asymmetric cyclization of some chlorohydrins catalyzed by optically active cobalt (salen)-type complexes, or in the enantiomeric selection of racemic oxiranes via halohydrins and /3-hydroxy sulfides. A useful three-step synthesis has been worked out from (S)-amino acids to (R)-alkyloxiranes as well as enantiomer resolution for chiral oxiranes by complexation gas chromatography. ... 

Via Halohydrin Cyclisations and Related Reactions 8 From Aldehydes and Ketones 8 Synthesis of Chiral Oxirans 10 Biosynthesis 12... 

Oxirans. - The synthesis of l,2-anhydro-3,4-di-0-benzyl-6-deoxy-a-D-glucopyranose and its conformational analysis have been reported. A range of epoxides have been prepared by base treatment of bromohydrins, which were made by reaction of hydrogen bromide with aldonolactones. A one-pot conversion of vicinal diols into epoxides employs halohydrin ester intermediates generated from cyclic orthoacetates and either acetyl bromide or trimethylsilyl chloride. Levoglucosenone has been transformed into l,6 3,4-dianhydro-p-D-talopyranose by way of a trn/w-iodo-acetoxylation of the alkene moiety... 

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