Abstract: A process for producing a synthesis gas mixture comprising hydrogen and carbon monoxide by noncatalytic partial oxidation of hydrocarbons in the presence of oxygen and carbon dioxide, in which at least one reactant gas comprising hydrocarbons, an oxygen-comprising reactant gas and a carbon dioxide-comprising reactant gas are fed into a partial oxidation reactor and reacted at a temperature in the range from 1200 to 1550° C. to give a product gas mixture comprising water, carbon monoxide and carbon dioxide, at least by separating a portion of the carbon dioxide from the product gas mixture and recycling it into the partial oxidation reactor, wherein the carbon dioxide fed into the partial oxidation reactor comprises additional imported carbon dioxide, giving a product gas mixture in the partial oxidation reactor that has a molar ratio of hydrogen to carbon monoxide in the range from 0.8:1 to 1.6:1.

Abstract: Enolic monoether and diether of adipic dialdehyde such as 6-methoxy-5-hexene-1-al, 1,6-dimethoxy-1,5-hexadiene, 1,6-bis-(2 hydroxy propoxy)-1,5-hexadiene are prepared by heating to a sufficiently high temperature for a Cope rearrangement, e.g., 150.degree. to 450.degree. C. of the corresponding monoether or diether of 1,5-hexadiene-3,4-diol.