engleski

Synthesis of propargylic epoxides

The synthesis of substituted propargylic epoxides for the purpose of stereoselective and regioselective ring opening by enzyme halohydrin dehalogenase was described. Using different nucleophiles, enantiomerically pure propargylic azidoalchohols and bicyclic triazole derivatives (N3-), propargylic oxazolidinone derivatives (OCN-) and propargylic nitriloalchohols (NC-) could be obtained [1]. Phenyl-, tert-butyl- and cyclopentyl- substituted epoxides were synthesized from the corresponding terminal acetylenes by introduction and epoxidation of a double bond. Also, p- and mtolyl derivatives were synthesized in a similar reaction sequence, starting from the corresponding iodotoluene and trimethylsilylacetylene. Furthermore, attempts to prepare the phenyl derivative in two ways (in a reaction sequence similar to the synthesis of tolyl derivatives ; and by derivatization of propargyl alchohol, oxidation of the obtained alchohol to aldehyde in several ways and its cyclization by sulfonium ylides), as well as the p-tolyl derivative by reacting p- iodotoluene with ethynylmagnesium bromide, were described.

propargylic epoxide ; Sonogashira ; epoxidation ; halohydrin dehalogenase

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