A process for making neo-enriched p-menthane intermediates is disclosed. Lewis acid-catalyzed rearrangement of an oxaspiro compound provides an aldehyde mixture comprising normal (II) and neo (III) p-menthane-3-aldehydes:
with the neo aldehyde (III) as the major product. The aldehyde mixture is readily oxidized to provide the corresponding carboxylic acids, and the acids are easily converted to a host of neo-enriched p-menthane esters or amides. The esters and amides are valuable as physiological coolants.
公开了一种制备富含新生代p-薄荷醛中间体的方法。Lewis酸催化的氧杂
螺环化合物重排提供了一种包含正常(II)和新生代(III) p-薄荷醛的醛混合物:其中新生代醛(III)是主要产物。这种醛混合物容易被氧化成相应的
羧酸,而这些酸则容易转化为大量的富含新生代p-薄荷酯或酰胺。这些酯和酰胺作为生理降温剂非常有价值。