A ONE STEP PROCESS FOR THE PREPARATION OF 2,6,6-TRIMETHYL-CYCLOHEXA-1,3-DIENE-1-CARBOXALDEHYDE,MORE COMMONLY KNOWN AS SAFRANAL FROM A MIXTURE OF 2,6,6-TRIMETHYL-CYCLOHEX-2-ENE-1-CARBOXALDEHYDE AND 2,6,6-TRIMETHYL-CYCLOHEX-1-ENE-1-CARBOXALDEHYDE MORE COMMONLY KNOWN AS-AND-CYCLOCITRALS RESPECTIVELY

摘要

A one step process for the preparation of safranal of structural formula V of the accompanying drawings, fromthe specific starting material a mixture of alpha - and beta - cyclocitrals of structural formula I and II respectivelyof the accompanying drawing under nitrogen atmosphere comprising:(i) treating a mixture of alpha - and beta - cyclocitrals of structural formula I and II respectively of the accompanying drawing ina ratio such as herein described with molecular bromine using a solvent such as herein described and, with or without a catalyst such as herein described to insitu obtain 3-bromo-2, 6, 6-trimethyl-cyclohex-1-ene-1-ecarboxaldehyde of structural formula IV of the accompanying drawing under conditions suchas herein described;(ii) treating the said bromo compound with a base such as herein described and under conditions such as herein described to obtain safranal of structural formula V of the accompanying drawing.