LEWIS ACID-CATALYZED, HIGH-PRESSURE, STEREOSPECIFIC, REGIOSPECIFIC, DIELS-ALDER CYCLOADDITION OF UNSUBSTITUTED 2-PYRONE - SHORT SYNTHESIS OF A RACEMIC A-RING PRECURSOR TO PHYSIOLOGICALLY ACTIVE 1-HYDROXYVITAMIN D-3 STEROIDS

[摘要] Bicyclic lactone 1, a racemic A-ring precursor to diverse physiologically active 1-hydroxyvitamin D-3 analogs, was prepared in 91% yield via 11-12 Kbar, Lewis acid-catalyzed, 4+2-cycloaddition of unsubstituted 2-pyrone.

[发布日期] 1994-10-10