Binaphthol-titanium-promoted, highly enantiocontrolled, Diels-Alder cycloadditions of electronically matched 2-pyrones and vinyl ethers: Streamlined asymmetric synthesis of an A-ring precursor to physiologically active 1α-hydroxyvitamin D3 steroids
作者:Gary H. Posner、Franck Eydoux、J.K. Lee、D.Scott Bull
DOI:10.1016/s0040-4039(00)78338-9
日期:1994.10
Bicyclic lactones 4, A-ringprecursors to diverse physiologically active 1α-hydroxyvitamin D3 analogs, were prepared in excellent yields and enantiomeric purities via chiral, non-racemic Lewis acid-promoted, mild, inverse-electron-demand 4+2-cycloadditions.