Thioacetaldehyde trimers

Miscellaneous Reactions. Sodium bisulfite adds to acetaldehyde to form a white crystalline addition compound, insoluble in ethyl alcohol and ether. This bisulfite addition compound is frequendy used to isolate and purify acetaldehyde, which may be regenerated with dilute acid. Hydrocyanic acid adds to acetaldehyde in the presence of an alkaU catalyst to form cyanohydrin the cyanohydrin may also be prepared from sodium cyanide and the bisulfite addition compound. Acrylonittile [107-13-1] (qv) can be made from acetaldehyde and hydrocyanic acid by heating the cyanohydrin that is formed to 600—700°C (77). Alanine [302-72-7] can be prepared by the reaction of an ammonium salt and an alkaU metal cyanide with acetaldehyde this is a general method for the preparation of a-amino acids called the Strecker amino acids synthesis. Grignard reagents add readily to acetaldehyde, the final product being a secondary alcohol. Thioacetaldehyde [2765-04-0] is formed by reaction of acetaldehyde with hydrogen sulfide thioacetaldehyde polymerizes readily to the trimer. 

CHjCHS The properties of monomeric thioaldehydes have been difficult to determine, because under normal experimental conditions they polynKri into cyclic dimers and trimers. Kroto and Landsberg were able to produce monomeric thioacetaldehyde as a product from the pyrolysis of 1,3,5-trimethyl-s-trithiane. The species is unstable, and was generated and detected in a fast flow systeni. The various species which coexist in this system at low pressures are summarized in Fig. 18. 

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