Application of a rhodium-catalyzed cyclization cycloaddition cascade strategy to the total synthesis of (−)-curcumol

Abstract

The first de novo total synthesis of (−)-curcumol was accomplished using a rhodium-catalyzed cyclization–cycloaddition cascade reaction as the key step.

Total Synthesis of Bipolamine I

“…To this end, the newly formed secondary alcohol was protected to form TBS ether 18, and this compound was then treated with samarium diiodide to smoothly cleave the bridging ether, resulting in hemiketal 19 (confirmed by X-ray crystallographic analysis). 19,20 With 19 in hand, activation to generate the thiocarbonate 20 followed by reductive deoxygenation and one-pot TBS deprotection provided (±)-bipolamine I (2) in good yield. 9,10 2 matched the reported NMR data from the isolation paper exquisitely (see Supporting Information for tabulated NMR shifts).…”