1708-25-4Relevant articles and documents
Concise synthesis of cis- and trans-theaspirones via oxonium ion-initiated pinacol ring expansion
Paquette, Leo A.,Lanter, James C.,Wang, Hui-Ling
, p. 1119 - 1121 (1996)
The odoriferous principle of black tea has been produced from 2,2-dimethylcyclopentanone. The reaction sequence begins with 1,2-addition of 5-lithio-2-methyl-2,3-dihydrofuran to this ketone and immediate acid-catalyzed ring expansion of the resulting carbinols to a separable pair of spiro ethers. Individual conversion of these diastereomers to α,β-unsaturated ketones is followed by tandem condensation with the methyllithium-lithium bromide complex and oxidation with pyridinium chlorochromate.
