The Michael-alkylation ring synthesis: piperidine and pyrrolidine construction

✍ Scribed by Joseph E. Dolfini; Dorothy M. Dolfini

• Book ID: 104240729
• Publisher: Elsevier Science
• Year: 1964
• Tongue: French
• Weight: 203 KB
• Volume: 5
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)89462-4

✦ Synopsis

The Mi&ael-alkylation sequence may be fundamentally visuallised as a two step process, involving a bifunctional molecule (I) contaking both mcleophilic and electrophilic groups and a typical polarized olefin molecule (II~A-CB,C~R,N~ etc.), taking place as followsr (I) (II) (III) The nucleophilic group, B, may typically be amino, carbanion, mercapto, etc. The leaving group, X, is typically halide or tosylate.

The product (III) of such a two step process, i.e., the formation of a Michael anion followed by intramolecular alkylation of the anion, may be either a haao or hetero-cyclic compound, depending on the nature of -BIi.

Corollary to the alkylation sequence is what may be termed the !4ichael_ecylation sequence in which a carboqvl function 8erve8 as the electropbilic cyclisation pranpter. This method has been attracting a umber of chemists since its inception at the hands of Kuhu and Osswdld 2103