Cw-2,3-epoxybutane

Epoxidation of cis-2-butene-l,4-diones.3 Enediones that can assume the all s-cis-conformation (A) are oxidized by Mo05 H20 HMPT (2 equiv.) stereospecif-ically to cw-2,3-epoxybutane-l,4-diones (1). 

Fig. 6 Progress of the reaction of cw-2,3-epoxybutane trapped in tri-o-thymotide with HBr gas as revealed by CP/MAS NMR [31]. Note that in spectrum (b) both reactant and product are present in an intact lattice. Also note the splitting of the product line (inset), showing doubling due to the presence of optically active product.

Epoxidation of cw-2-butene gives meso-2,3-epoxybutane fnms-2-butene gives a racemic mixture of (2R,3R) and (2S,3S)-2,3-epoxybutane. 

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