Hydroformylation of (+)(S)-3-methylpent-1-ene

Abstract

In the hydroformylation of (+)(S)-3-methylpent-1-ene the extent of racemization of the synthesized dissymmetric aldehydes is shown to decrease with increasing pressure of carbon monoxide; the ratio of erythro- to threo-2,3-dimethylpentanal formed differs considerably from the diastereoisomeric equilibrium value.

Racemic 4-methylhexanal is shown to arise from racemic 3-methylpent-1-ene and therefore gives some indication of the relative rates of hydroformylation and isomerization of the olefinic substrate.

The secondary butyl group exerts, under conventional ‘oxo’ conditions, a weak asymmetric induction in the formation of 2,3-dimethylpentanal, probably connected to the steric requirements in the complex formation between the olefin and the cobalt catalyst.