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.
揭示了一种制备富含新生代p-薄荷烷中间体的过程。Lewis酸催化的氧杂
螺环化合物重新排列提供了包含正常(II)和新生代(III)p-薄荷烷-3-醛的醛混合物:其中新生代醛(III)为主要产物。该醛混合物容易氧化为相应的
羧酸,并且这些酸易于转化为一系列富含新生代p-薄荷烷酯或酰胺。这些酯和酰胺作为生理制冷剂具有很高的价值。