β-Alkylthio-substituted α, β-unsaturated aldehydes

1. The reaction of sodium alkanethiolates with the acetals of α-halo-substituted α, β-unsaturated aldehydes leads to the corresponding β-alkylthio-substituted derivative independent of the nature of the halogen or of the presence of an alkyl group in the β position, and also independent of the character of the employed solvent. 2. In acid medium the β-alkylthio-substituted acetals of α, β-unsaturated aldehydes are hydrolyzed at room temperature without cleaving the C-S linkage to give the corresponding β-alkylthio-substituted α, β-unsaturated aldehydes. The latter under mild conditions form derivatives at the carbonyl group without changing the carbon skeleton. This reaction when run with heating leads to cyclization and the formation of pyrazole derivatives. Prolonged heating of the butylthioacrolein with excess butanethiol leads to the reaction product at the two reaction centers, and specifically to 1,1,3,3-tetrabutylthiopropane.