2-methyl-4-pheny1-1,3-dioxolane

Abstract

The sensory properties of the diastereomeric enantiomer pairs and of the pure enantiomers of the compound 2-methyl-4-phenyl-1,3-dioxolane are described. The cis compounds (2 S,4 R)-2-methyl-4-phenyl-1,3-dioxolane and (2 S,4 R)-2-methyl-4-phenyl-1,3-dioxolane are the most sensorially valuable. These enantiomers and mixtures thereof are particularly suitable for use as a sensorially active substance, for example as a fragrance.

What is claimed is:  
     
         1 . (2 R,4 S)-2-Methyl-4-phenyl-1,3-dioxolane or (2 S,4 R)-2-methyl-4-phenyl-1,3-dioxolane, in particular for use as sensorially active substance.  
     
     
         2 . The use of a substance from the group comprising (2 S,4 R)-2-methyl-4-phenyl-1,3-dioxolane, (2 R,4 S)-2-methyl-4-phenyl-1,3-dioxolane and mixtures thereof  
       as sensorially active substance.  
     
     
         3 . A mixture comprising one part by weight of (2 S,4 R)-2-methyl-4-phenyl-1,3-dioxolane and/or (2 R,4 S)-2-methyl-4-phenyl-1,3-dioxolane and less than two parts by weight of (2 R,4 R)-2-methyl-4-phenyl-1,3-dioxolane and/or (2 S,4 S)-2-methyl-4-phenyl-1,3-dioxolane, in particular for use as sensorially active substance.  
     
     
         4 . A mixture comprising one part by weight of (2 S,4 R)-2-methyl-4-phenyl-1,3-dioxolane and/or (2 R,4 S)-2-methyl-4-phenyl-1,3-dioxolane and less than one part by weight of (2 R,4 R)-2-methyl-4-phenyl-1,3-dioxolane and/or (2 S,4 S)-2-methyl-4-phenyl-1,3-dioxolane, in particular for use as sensorially active substance.  
     
     
         5 . A process for the preparation of a mixture as claimed in either of claims  3  and  4 , which comprises acetalating acetaldehyde at a temperature of 20° C. or below with racemic or enantiomerically pure 1-phenyl-1,2-ethanediol.  
     
     
         6 . A process for the preparation of (2 S,4 R)-2-methyl-4-phenyl-1,3-dioxolane and/or (2 R,4 S)-2-methyl-4-phenyl-1,3-dioxolane which comprises bringing (2 S,4 S)-2-methyl-4-phenyl-1,3-dioxolane and/or (2 R,4 R)-2-methyl-4-phenyl-1,3-dioxolane, dissolved in a solvent, to a temperature of 20° C. or below, preferably 0° C. or below.  
     
     
         7 . The use of a mixture as claimed in either of claims  3  and  4  as a fragrance.