Asymmetrization of a meso 1,2-enediol bis(trimethylsilyl) ether using a (S)-BINOL monoisopropyl ether(BINOL-Pr(i))-tin tetrachloride complex: An alternative route to (-)-ketodicyclopentadiene and (-)-ketotricyclononene

Article abstract of DOI:10.1016/S0040-4039(97)01488-3

A tricyclic mesa 12-enediol bis(trimethylsilyl) ether having an endo-tricyclo[4.2.1.0^2,5]nonene framework has been asymmetrically desymmetrized by protonation with a complex generated from (S)-BINOL monoisopropyl ether (BINOL-Pr(i)) and tin tetrachloride to give the optically enriched acyloin in 90% ee. The chiral acyloin thus obtained has been transformed into two versatile chiral building blocks, (-)-ketodicyclopentadiene and (-)-ketotricyclononene, in optically pure forms via a sequence involving concurrent enzymatic acetylation and optical purification.