| 摘要 |
Enantiomer-free 2,2,4-trisubstituted 1,3-dioxolanes of the general formula: <IMAGE> I wherein R1 and R2 are either the same and are (a) hydrogen or (b) alkyl groups with 1 to 4 C atoms or (c) aryl groups or (d) arylalkyl groups or R1 and R2 together are a 1,4-butanediyl or 1,5-pentanediyl group, and X is either a hydroxy group or, with the assumption that R1 and R2 are not aryl groups, NHR3 wherein R3 is alkyl with 1 to 8 C atoms or aryl, are produced by electrolysis of a substated theronic acid or erythornic acid or a salt thereof into a substituted 1,3-dioxolane-4-carbaldehyde. The substituted 1,3-dioxolane-4-carbaldehyde is converted by reduction or reductive amination, without being ioslated, into the enantiomer-free 2,2,4-trisubstituted 1,3-dioxolane. A substantial advantage of the electrochemical process is that only carbon dioxide and hydrogen are produced which escape by themselves as gases from the electrolyte.
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