The<unk>  is a series of chemical reactions designed to convert a carboxylic acid to a higher carboxylic acid homologue (ie. contains one additional carbon atom) and is considered a homologization process. Named for the German chemists Fritz<unk>  (1885-1969) and Bernd<unk>  (1902-1978),<unk>  is a popular method of producing beta-amino-acids from alpha-amino-acids.  Acid chlorides react with diazomethane to give diazoketones.  In the presence of a nucleophile (water) and a metal catalyst (Ag2O), diazoketones will form the desired acid homologue.
While the classic<unk>  uses thionyl chloride to convert the starting acid to an acid chloride, any procedure can be used that will generate an acid chloride.
Diazoketones are typically generated as described here, but other methods such as diazo-group transfer can also apply.
Since diazomethane is toxic and violently explosive, many safer alternatives have been developed, such as the usage of ynolates or trimethylsilyldiazomethane.
Arndt-Eistert synthesis
Chiral pool synthesis
Fukuyama indole synthesis
Fatty acid metabolism
Oogenesis
Dimroth rearrangement
Lipogenesis
Wnt signaling pathway