N ‐Methyl‐ C ‐(trichlortitanio)formimidoylchlorid. Ein effizientes Reagenz zur Homologisierung von Aldehyden und Ketonen zu α‐Hydroxy‐carbonsäureamiden

N ‐Methyl‐ C ‐(trichlorotitanio)formimidoyl Chloride, a Highly Efficient Reagent for Homologations of Aldehydes and Ketones to α‐Hydroxycarboxamides The known title compound 6 formed by addition of titanium tetrachloride to methyl isocyanide in methylene chloride adds to the carbonyl group of aldehydes and ketones. The adducts 7 are hydrolized to N ‐methyl‐α‐hydroxycarboxamides 8 which are (from ketones) or are not branched (from aldehydes) in the α‐position. The yields in this new modification of the Passerini reaction are near 90%, also with readily enolized ketones such as acetone and acetophenone. In contrast to the previously used organotitanium reagents of the type RTiX 3 , the preparation of the reagent 6 does not require any Li‐, Mg‐ or Zn‐derivative as a precusor.