Carbon Dioxide → HCID 23050686, compound

Participants

Reaction Steps

The 1-chloro-2-methyl-2-phenylpropane which can be prepared according to F. C. Withmore et al., J. Am. Chem. Soc. 65 (1943), 1469 by reacting benzene with methallyl chloride is converted in a yield of 82% by a Grignard reaction and subsequent working up with dry ice and hydrolysis into 3-methyl-3-phenylbutyric acid, the latter is reduced (91% yield) with lithium alanate to the alcohol, this is chlorinated in a further step with thionyl chloride in a yield of 75%, and the resulting 1-chloro-3-methyl-3-phenylpropane is reacted with magnesium and then with ethyl orthoformate to give 4-methyl-4-phenyl-1-pentanal in a yield of only 38%. The total yields obtained in this process are only about 21%. Another disadvantage is the fact that some of the reaction steps used are very expensive. In contrast, Ia as well as other, novel 4-methyl-4-phenyl-1-pentanals of the general formula I can be prepared with surprisingly good olfactory properties, in a simple manner and in good yields from 3-methyl-3-phenyl-1-butenes of the general formula II (cf. the previously unpublished patent application No. P 35 36 929.9), which has recently become very readily available.

Provenance & Evidence