Method for preparing primary alcohols having alkyls branched at the second carbon

DETAILED DESCRIPTION The preferred gas mixture to be used in carrying out the method of this invention is a synthetic gas formed by cracking methane and having a molar ratio H.
sub.
2 /CO between about 1.
6/1 and 2.
2/1, most preferably between about 1.
8/1 and 2/1.
This is used without further preliminary treatment to hydrogenate an aldehyde having a branch at the alpha carbon.
The residual gas is hydrogendepleted to leave a composition between about 1.
1/1 and 1.
5/1 which is suitable for use in the Oxo process, thereby eliminating the expensive and burdensome steps used in the prior art to prepare hydroformylation agent specially.
In particular the effluent gas mixture can be used directly for preparing aldehydes, which can subsequently be submitted to the above described steps of aldolization and crotonization to aldehydes having alkyl branching at the second carbon and useful in the present hydrogenation step.
The hydrogenation catalysts useful for the present hydrogenation by a H.
sub.
2 /CO mixture are in particular those based on copper which are specially appropriate because they are insensitive to carbon monoxide.
However any hydrogenation catalyst which is insensitive to carbon monoxide can likewise be used.
When copper is used, it can contain as primers, promoters or the like, one or more other metals or metal oxides, with the exception of group VIII elements in the periodic chart; thus cobalt and nickel are contraindicated because they would cause deterioration of catalyst by forming metal carbonyls which would dissolve in the reaction products.
Among the catalysts, Adkins catalysts based on copper and chromic oxide Cr.
sub.
2 O.
sub.
3 are specially suitable, particularly when stabilized by stabilizers such as barium oxide.
These catalysts can be prepared in various known ways.
In a particularly convenient procedure, an aqueous alkali is added to an aqueous solution of the nitrates of the respective metals.
The precipitated hydroxide or hydrated oxide is successively washed, dried, calcined and formed into pellets