Aldehydes and ketones add onto the germanium-oxygen bond of triethylmethoxy-and diethylmethoxy-chlorogermanes with formation of the corresponding germanium a etals, the stability, the mode of thermal decompositionThe germanium acetals of hexafluoroacetone are stable. &Elimination reactions are observed from germanium acetals of chloral and hexachloroacetone. The decomposition of the germanium acetals of the aldehydes and ketones takes place, in the presence of HzPtCla, to give the corresponding acetals of the starting carbonyl compounds and trialkylgermanium oxides.Additions and decompositions of the same type are observed in the action of the aliphatic aldehydes on the trialkyl(alky1thio)-and dialkyl(alky1thio)-chlorogermanes. Chloral gives a reversible insertion reaction, however, at 90". besides the ,!?-elimination reaction, a chlorine-methylthio exchange reaction is also observed with formation of tri(methy1thio)acetaldehyde and triethylgermanium chloride.The influence of the inductive effects of the substituents on the germanium or on the carbonyl group in the course of these reactions as well as the catalytic action of the chloroplatinic acid or of zinc chloride seem to confirm the addition mechanism considered. and certain properties o 2 which have been investigated.

Aliphatische Aldehyde wie Acetaldehyd (II) reagieren ebenso wie Benzaldehyd und Crotonaldehyd unter Einschiebung in die Ge‐O‐Bindung mit den Germanen (I) in Gegenwart von Hexachloroplatinsäure zu den Derivaten (III).