Alkenes from β-lithiooxyphosphonium ylides generated by trapping α-lithiated terminal epoxides with triphenylphosphine
نویسندگان
چکیده
Terminal epoxides undergo lithium 2,2,6,6-tetramethylpiperidide-induced α-lithiation and subsequent interception with Ph(3)P to provide a new and direct entry to β-lithiooxyphosphonium ylides. The intermediacy of such an ylide is demonstrated by representative alkene-forming reactions with chloromethyl pivalate, benzaldehyde and CD(3)OD, giving a Z-allylic pivalate, a conjugated E-allylic alcohol and a partially deuterated terminal alkene, respectively, in modest yields.
منابع مشابه
Convergent synthesis of conjugated 1,2-disubstituted E-allylic alcohols from two aldehydes and methylenetriphenylphosphorane.
β-Lithiooxyphosphonium ylides, made in situ from an aldehyde and methylenetriphenylphosphorane, react with a second aldehyde to form E-allylic alcohols. α-Branching and α,β-unsaturation in the second aldehyde, together with the lack of further substitution on the phosphorane carbon play important roles in selectivity. A range of these aldehydes, in addition to aromatic aldehydes as the second a...
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