119162-95-7Relevant academic research and scientific papers
A stereocontrolled approach to electrophilic epoxides
Meth-Cohn, Otto,Moore, Clive,Taljaard, Heinrich C.
, p. 2663 - 2674 (2007/10/02)
Lithium t-butyl hydroperoxide (easily generated by addition of an alkyl-lithium to anhydrous t-butyl hydroperoxide in THF solution) is a powerful reagent for the epoxidation of electrophilic alkenes at -20 to 0 °C under full stereocontrol. Thus αβ-unsaturated esters, sulphones, sulphoximines, and amides are readily epoxidised with complete regio- and stereo-specificity and with considerable chiroselectivity (20-100%) when appropriate chiral auxiliaries such as menthyl, 8-phenylmenthyl, or a camphor-sulphonamide derivative are used. Asymmetric αβ-unsaturated sulphoximines undergo epoxidation with 100% diastereoselectivity. The only exceptions to stereocontrol noted are heavily substituted maleate esters such as di-t-butyl maleate. The αβ-epoxy amides are shown to be valuable sources of the corresponding epoxy ketones by treatment with an organolithium, allowing a stereo- and chemoselective entry in high yield to these useful intermediates.
A Powerful New Stereo-controlled Method for Epoxidation of Electrophilic Alkenes
Clark, Carol,Hermans, Patricia,Meth-Cohn, Otto,Moore, Clive,Taljaard, Heinrich C.,Vuuren, Gerda van
, p. 1378 - 1380 (2007/10/02)
t-Butyl hydroperoxide and an alkyl-lithium in dry tetrahydrofuran are shown to epoxidise α,β-unsaturated esters and sulphones efficiently in a stereo- and regio-specific manner, while esters of chiral alcohols undergo diasterefacially selective epoxidatio
