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 aldehyde also provided synthetically useful access to E-allylic alcohols.
第二醛中α-支化和α,β-不饱和以及
磷烷碳上缺乏进一步的取代在选择性方面起着重要作用。除了以芳香醛作为第二醛外,这些醛还提供了合成 E-烯丙基醇的有用途径。