The Syntheses of 4,4′-(1,n-Dioxaalkane)-bisbenzaldehydes and 4,4′-(1,n-Dioxaalkane)-bis(α-methoxy Phenylacetic Acids)

The syntheses of 4,4′-(1,n-dioxaalkane)-bis(α-methoxyphenylacetic acids) were conducted using a base-catalyzed reaction. The reactants were potassium hydroxide (or lithium hydroxide/lithium chloride), bromoform, methanol and 4,4′-(1,n-dioxaalkane)-bisbenzaldehydes. The aldehyde starting materials were prepared using the Williamson ether synthesis, by condensing p-hydroxybenzaldehyde and 1,n-dibromoalkanes with lithium hydride in ethanol. The effect of varying the hydrocarbon length in the dioxaalkane bridge unit is a significant consideration (the number of CH₂ units in the bridge varying from two to eight) in their acid salt formation.

     

P,P,P',P'-四氯联苯二膦的合成

芳环的二氯膦化产物是有机合成中的重要中间体,广泛应用于不对称合成领域制备手性膦配体,紫外光固化领域合成膦酰氧光引发剂等。文献报道的芳环二氯膦化方法有如下几种：(1)由芳基溴制备格氏试剂或由芳基溴直接锂化,然后与三氯化膦反应。(2)由芳基溴经格氏试剂或直接锂化,然后与二(二乙胺基)氯化膦反应,最