Catalytic Diastereoselective Synthesis of Diquinanes from Acyclic Precursors.

摘要: Upon exposure of up to 10 mol % tributylphosphine, electron-deficient 1,7-enynes undergo [3 + 2] cycloaddition afford bicyclo[3:3:0] ring systems. In all but one case, products were obtained in >95:5 de, as determined by 1H NMR. This methodology enables concise and diastereoselective access diquinane systems, whereby three contiguous stereogenic centers are set a single manipulation.