1,6-Asymmetric induction utilizing Asymmetric desymmetrization by diastereoselective C-O bond fission of the 4-substituted bicyclic acetal: Application to a synthesis of (-)-frontalin

Article abstract of DOI:10.1248/cpb.46.217

1,6-Asymmetric induction was achieved in the acid-induced diastereoselective acetal cleavage reaction of a 4-substituted bicyclic acetal 8 bearing a chiral sulfinyl group. On treatment with titanium tetrachloride and 2,6-disubstituted pyridine bases, 8 gave a synthetically versatile 3,3-disubstituted dihydropyran derivative 9a with moderate diastereoselectivity. The utility of this chiral synthon was successfully demonstrated by a formal synthesis of (-)-frontalin.