factors but can be determined empirically by the skilled artisan without undue effort typically a temperature in the range from about 50 u00b0 c to about 175 u00b0 c more preferably about 60 u00b0 c to about 150 u00b0 c most preferably about 75 u00b0 c to about 120 u00b0 c is conducive to internal hydroformylation of the acetal temperatures above these in the preferred ranges increase the hydroformylation of the unsaturated terminal carbon atom the pressure during hydroformylation is advantageously at least about 500 psia pounds per square inch absolute more preferably 750 to about 2000 psia pressures in the range from about 750 to about 1500 psia are especially preferred a gaseous mixture of hydrogen and carbon monoxide are reacted with the acrolein acetal to effect hydroformylation inert diluent gases such as nitrogen can also be present in the mixture the carbon monoxide and hydrogen are advantageously present in the gaseous mixture in a volume ratio in the range from 1 4 to 4 1 preferably from 1 2 to 2 1 advantageously a stoichiometric excess of carbon monoxide and hydrogen is employed with the acetal of acrolein the hydroformylation of the acrolein acetal produces the isomer hydroformylated on the terminal position as well as other products these other products were.