Decarboxylation alkylation

A similar alkylative decarboxylation takes place during the thermolysis of 1-alkoxy-carbony lbenzotriazoles.[8a]... 

Lateral chain modifications on QDO and PDO have been well documented in the literature. The described reactions have shown modifications in specific functional group—i.e., acylations, alkylations, decarboxylations, hydrolysis, rearrangements, substitutions—or the production of a new heterocycle, fusioned or not. Examples of the most recent descriptions are depicted in Fig. 6 [64-66],... 

Finkbeiner extended the sequence of a-carboxylation and alkylation-decarboxylation to 3-phenylhydantoin (7). Reaction with MMC, followed by esterification... 

This reaction was studied comprehensively by Krapcho beginning as early as 1967. It is an alkali halide promoted alkylative decarboxylation of active esters (e.g., )8-keto esters, fi-diesters, a-cyano esters) in polar or dipolar aprotic solvents (e.g., DMF, DMSO, HMPA,) and is generally known as the Krapcho decarboxylation or Krapcho condition. Occasionally, it is also referred to as the Krapcho decarbalkoxylation. In addition, the corresponding decarboxylation on methyl esters is known as the Krapcho decarbomethoxylation, and the decarboxylation of ethyl esters is referred to as the Krapcho decarbo-ethoxylation. ... 

It has also been found that electron-withdrawing substituents facilitate the alkylative decarboxylation, whereas steric hindrance might retard the occurrence of such reaction. For example, diethyl and dimethyl disubstituted malonates do not practically undergo the decarboxylation when heated in DMS0/H20. ... 

Biosynthesis of secondary metabolites involves numerous different mechanisms and reactions that are enzymatically catalyzed using several common mechanisms such as acylation, alkylation, decarboxylation, phosphorylation, hydride transfer, oxidation, elimination, reduction, condensation, rearrangement, and so on. The biosynthetic pathway may undergo changes due to natural causes (e.g., vimses or environmental changes) or unnatural causes (e.g., chemical or radiation) in an attempt to adapt or provide long life to the organism. 

FIGURE 19.62 The alkylation-decarboxylation sequence for the synthesis of substituted acetic acids from diethyl... 

---