This invention provides a process for producing 2-vinyl-1,3-dioxane compounds rapidly and efficiently by contact of a mixture of acrolein and a 1,3-propanediol compound with solid cation exchange resin in acid form. There is further provided a process for conversion of acrolein into 3-(1',3'-dioxane)propionaldehyde derivatives.
Mixed cyclic acrolein glycerol acetals can be obtained by reacting acrolein with glycerol in the presence of a solid acidic catalyst and by a distillation workup in a higher space-time yield and in very high selectivity in comparison to the state of the art if the reaction is carried out in the presence of the reaction mixture as solvent, which mixture consists essentially of acrolein, glycerol, cyclic acrolein glycerol acetals and water, and in the absence of heterogeneous solvents and, to the extent necessary, the reaction mixture freed of catalyst is compounded prior to being worked up by distillation with such an amount of pH-increasing substance that it exhibits a pH in a range of 4.5 to 7 in tenfold dilution with water. The reaction preferably takes place at 10.degree. to 30.degree. C. using strongly acidic organic or inorganic ion exchangers.
A process for producing 1,4-butanedial monoacetal by reacting acrolein acetal with a synthesis gas containing carbon monoxide and hydrogen, in the presence of a rhodium catalyst and an accelerator of formula (I) ##STR1## wherein R.sup.1 and R.sup.2 each, independently, denote a hydrogen atom, a C.sub.1 -C.sub.20 alkyl group or a C.sub.6 -C.sub.20 aryl group, or R.sup.1 and R.sup.2 together form a --(CH.sub.2).sub.n -- group, n is an integer of from 2 to 7, R.sup.3 and R.sup.4 each, independently, denote halogen or a trifluoromethyl group, and p and q are each, independently, an integer of from 0 to 3, which process can also be extended to the hydroformylation of other compounds which contain an olefin group in a terminal position.
A series of new 1,3-dioxane derivatives are disclosed. These compounds have an outstanding anti-peptic ulcerative activity and are useful as novel anti-peptic ulcer agents. Such compounds are synthesized by reacting a 1,3-butanediol derivative with suitable ketone.
A process for the hydroformylation of terminally unsaturated olefinic compounds by carrying out the hydroformylation under a continuously decreasing partial pressure of carbon monoxide to achieve a high linear to branched-chain ratio of aldehydes without a reduction in reaction rate, said process comprising conducting the hydroformylation at an initial total carbon monoxide and hydrogen pressure of from 40 to 500 psia the mole ratio of hydrogen to carbon monoxide being 1:1 or greater and adjusting downward the partial pressure of CO continuously until at least a 25% reduction in the partial pressure of carbon monoxide in the range of from 1 to 40 psi absolute is reached.
This invention provides a process for producing 3-(1',3'-dioxane)propionaldehyde or 3-(alkyl-1',3'-dioxane)propionaldehyde in over 70 weight percent yield by the reaction of 2-vinyl-1,3-dioxane or 2-vinyl-alkyl-1,3-dioxane with hydrogen and carbon monoxide under hydroformylating conditions.
