Suzuki J, Miyano N, Yashiro S, Umezawa T, Matsuda F. Total synthesis of (-)-kainic acid and (+)-allo-kainic acid through SmI
2-mediated intramolecular coupling between allyl chloride and an α,β-unsaturated ester.
Org Biomol Chem 2017;
15:6557-6566. [PMID:
28748237 DOI:
10.1039/c7ob01427a]
[Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A 3,4-disubstituted pyrrolidine ring was effectively cyclized through SmI2-mediated reductive coupling between allyl chloride and an α,β-unsaturated ester, although little has been reported about SmI2-promoted C-C bond formation of an allyl chloride with an α,β-unsaturated ester. Selection of either the 3,4-cis- or 3,4-trans-selective cyclization can be accomplished simply by changing the additives from NiI2 to HMPA during reductive cyclization conducted in H2O-THF. Total synthesis of (-)-kainic acid and (+)-allo-kainic acid, which are pyrrolidine alkaloids used in neuroscience and neuropharmacology as useful molecular probes, was successfully achieved by using the stereo-complementary ring closure reactions promoted by SmI2 for the construction of the 2,3,4-trisubsituted pyrrolidine scaffold of kainoids.
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