Enantiomerically Pure 6-Substituted 2-Oxo-cyclohexanecarboxylates by Conjugate Addition of Cuprates to Asymmetric Shielded 2-Oxo-cyclohexenecarboxylates

Article abstract of DOI:10.1016/0040-4020(95)00676-Y

Asymmetric shielded 2-oxo-cyclohexenecarboxylates 6n and 6x were prepared by transesterification of 2-oxo-cyclohexanecarboxylate 2 with camphor derived concave alcohols 1n and 1x and by subsequent introduction of a double bond via phenylselenides.Diastereoselective conjugate addition of equimolar amounts of mixed cuprates at -78 deg C and deprotection by methanolysis gave enantiomerically pure 6-substituted 2-oxo-cyclohexanecarboxylates 14-19 and ent-14-19, valuable as chiral building blocks in natural product synthesis.