Synthesis of Kainoids and C4 Derivatives

Kainic Acid-Based Agonists of Glutamate Receptors: SAR Analysis and Guidelines for Analog Design

A comprehensive survey of kainic acid analogs that have been tested for their biological activity is presented. Specifically, this review (1) gathers and compares over 100 kainoids according to a relative activity scale, (2) exposes structural features required to optimize affinity for kainate receptors, and (3) suggests design rules to create next-generation KA analogs. Literature SAR data are analyzed systematically and combined with the most recent crystallographic studies. In view of the renewed interest in neuroactive molecules, this review aims to help guide the efforts of organic synthesis laboratories, as well as to inform newcomers to KA/GluK research.

Total Syntheses of (+)-α-Allokainic Acid and (-)-2- epi-α-Allokainic Acid Employing Ketopinic Amide as a Chiral Auxiliary

Asymmetric Michael reaction of iminoglycinate 4 to α,β-unsaturated esters had been developed with >98:<2 diastereoselectivity. A reverse of diastereoselectivity for Michael reaction could be achieved by the replacement of lithium enolate with magnesium enolate. This methodology was applied to the total syntheses of (+)-α-allokainic acid 1 and (-)-2- epi-α-allokainic acid 6 each in 11 synthetic steps starting from 4 in 17.8 and 18.0% yields, respectively.