Total synthesis of (-)-alpha-kainic acid by (-)-sparteine-mediated asymmetric deprotonation-cycloalkylation.
[reaction: see text] We report a new enantioselective synthesis of (-)-alpha-kainic acid from d-serine methyl ester hydrochloride, based on a (-)-sparteine-mediated asymmetric deprotonation of an intermediate carbamate that, by stereospecific anti S(N)'S(E)' intramolecular cycloalkylation, leads to the pyrrolidine ring precursor of (-)-alpha-kainic acid, in high yield and diastereoselectivity. The intermediate pyrrolidine was further transformed to (-)-alpha-kainic acid in three steps.
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany.
M Montserrat
MM
Martinez
Dieter
D
Hoppe
D000478:Alkylation; D003500:Cyclization; D007608:Kainic Acid / Q000138:chemical synthesis*; D011522:Protons; D013034:Sparteine / Q000737:chemistry*
D011522:Protons; D013034:Sparteine; D007608:Kainic Acid