Synthesis and properties of alkylthioethanals

Abstract

A method, allowing alkylthioethanals to be synthesized in 80-93% yields, has been developed. It comprises the hydrolysis of bis-1,1-alkoxy-2- alkylthioethanes using two-phase system water - organic solvent. The method is applicable for both common aldehydes bearing lower radicals (R = Pr, Bu) and hitherto unknown highly boiling aldehydes (R = C7H15, C8H17, PhCH2). It has been found that alkylthioethanals can spontaneously trimerize into 2,4,6-alkylthiotrioxanes. In basic media (1N NaOH, KF/Si(OEt)4/EtOH), alkylthioethanals affords the products of aldol self-condensation in up to 60% yield (1H NMR). In competitive interaction (cross-aldol condensation) of butylthio- and alkoxyethanals with furan- or thiophen-2-carbaldehydes, the reactivity of sulfur-containing carbanions was shown to be more than six times higher than that of the alkoxy analogs. © ARKAT-USA, Inc.