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Total syntheses of (-)-alpha-kainic acid and (+)-alpha-allokainic acid via stereoselective C-H insertion and efficient 3,4-stereocontrol.

ABSTRACT: Reported herein is a novel approach to the total syntheses of (-)-alpha-kainic acid and (+)-alpha-allokainic acid, where the stereochemistries on C(2), C(3), and C(4) of the pyrrolidine core were introduced efficiently and selectively. A regio- and stereoselective C-H insertion reaction was utilized to prepare the gamma-lactam as an intermediate. A Michael-type cyclization of phenylsulfone with a conjugated acetylenic ketone was developed to prepare the tricyclic ketone as a key intermediate for (-)-alpha-kainic acid. Subsequently, a stereoselective dephenylsulfonylation was carried out successfully to secure the cis relationship at C(3) and C(4) centers. An unprecedented acetylation on the phenylsulfone, followed by a stereoselective dephenylsulfonylation, secured the trans relationship at C(3) and C(4) centers in (+)-alpha-allokainic acid.

SUBMITTER: Jung YC

PROVIDER: S-EPMC2536682 | biostudies-literature | 2007 Dec

REPOSITORIES: biostudies-literature

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Total syntheses of (-)-alpha-kainic acid and (+)-alpha-allokainic acid via stereoselective C-H insertion and efficient 3,4-stereocontrol.

Jung Young Chun YC Yoon Cheol Hwan CH Turos Edward E Yoo Kyung Soo KS Jung Kyung Woon KW

The Journal of organic chemistry 20071129 26

Reported herein is a novel approach to the total syntheses of (-)-alpha-kainic acid and (+)-alpha-allokainic acid, where the stereochemistries on C(2), C(3), and C(4) of the pyrrolidine core were introduced efficiently and selectively. A regio- and stereoselective C-H insertion reaction was utilized to prepare the gamma-lactam as an intermediate. A Michael-type cyclization of phenylsulfone with a conjugated acetylenic ketone was developed to prepare the tricyclic ketone as a key intermediate for ...[more]

PMID: 18044924

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