Propionaldehyde pyrolysis

For the large activated propionaldehyde molecule, the pyrolysis step appears to be favored and the equilibrium with the propylene oxide shifts in its direction. The products given for this scheme appear to be consistent with experimental results [38], The further reaction history of the products has already been discussed. 

Neither the thermal nor the cobalt-catalyzed decomposition of 3-butene-2-hydroperoxide in benzene at 100 °C. produced any acetaldehyde or propionaldehyde. In the presence of a trace of sulfuric acid, a small amount of acetaldehyde along with a large number of other products were produced on mixing. Furthermore, on heating at 100°C., polymerization is apparently the major reaction no volatile products were detected, and only a slight increase in acetaldehyde was observed. Pyrolysis of a benzene or carbon tetrachloride solution at 200°C. in the injection block of the gas chromatograph gave no acetaldehyde or propionaldehyde, and none was detected in any experiments conducted in methanol. 

In an alternative approach to this group of alkaloids, ( )-elaeokanine A (9) has been made by an intramolecular imino-Diels-Alder reaction. Pyrolysis of (15) in toluene solution yielded a mixture of the diastereoisomers (16), which, by a sequence of reactions, were converted into ( )-elaeokanine A (9).5 The possible derivation of the Elaeocarpus alkaloids from a common biosynthetic intermediate 3-(l-pyrrolinium)propionaldehyde (17), and the use of (17) in a synthetic approach to these alkaloids, have been discussed.6... 

Propionaldehyde, a product of the pyrolysis could have hardly been formed... 

The occurrence of chains at temperatures slightly above 100 °C was proved by Volman and Brinton ° . They found that methyl radicals from the pyrolysis of di-/-butyl peroxide induce the chain decomposition of propionaldehyde in the temperature range 122-156 °C. 

Larson, U.S. pal. 2,448,375 (1948 to du Pont) from ethanol and carbon monoxide using a boron trifluoride catalyst Loder, U.S. pats. 2,135,448 2,135,451 2,135,453 (1939 to du Pont) by oxidation of propionaldehyde Hasche, U.S, pat. 2,294,984 (1942 to Kodak) from natural gas by the Fischer-Tropsch process as a byproduct in the pyrolysis of wood by the action o( microorganisms on a variety of materials in small yields. Very pure propionic acid can be obtained from propionitrile. 

In detail, at high pyrolysis temperatures, cellulose produces a liquid fraction that mainly consists of water along with small amoimt of acetaldehyde, propionaldehyde, furan, acetone, butanedione and methanol. It was found that dehydration at C(5)-C(6)... 

Pyrolysis GC of alcohol ethoxylates in the presence of P2O5 yields acetaldehyde, 1,4-dioxane, and alkenes corresponding to the initiator alcohols. If the surfactant contained propylene oxide groups, propionaldehyde and dimethyldioxane are also seen. Branched initiators can be distinguished from straight-chain alcohols because the former give many isomeric alkenes after pyrolysis (76). 

Pyrolysis with P2O5 at 500- C to form alkenes, acetaldehyde, and 1,4-dioxane Pyrolysis with P2O5 at 600-C to form alkenes, acetaldehyde, 1,4-dioxane, propionaldehyde, and dimethyldioxane... 

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