Guan YK, Li YL. The first preparation of enantiopure 1-methyl-7-oxabicyclo[2.2.1]heptan-2-one, a versatile chiral building block for terpenoids.
Chirality 2005;
17:113-8. [PMID:
15669060 DOI:
10.1002/chir.20095]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Methods for the resolution of (+/-)-1-methyl-7-oxabicyclo[2.2.1]heptan-2-one 1, a versatile chiral building block for terpenoids, have been investigated. While no efficient result was obtained with kinetic resolution methods, both enantiomers of 1 were prepared optically pure for the first time via esterification of the reductive products of 1 with (+)-mandelic acid and oxidation of the saponified products of diastereomer esters, in an overall yield of 70%. The absolute configurations of (-)-1 and (+)-1 were determined as (1S,4R)-(-)-1 and (1R,4S)-(+)-1 by the CD exciton chirality method and confirmed by Moshers (1)H-NMR method.
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