Asymmetric dihydroxylation of a series of poly-O-methoxymethyl-1,3-diarylpropenes with AD-mix-α or AD-mix-β and subsequent acid-catalyzed cyclization of the intermediate syn-diols permits the first synthetic access to all four diastereoisomers of free phenolic flavan-3-ols in high enantiomeric excess and yield.
References
1.
PorterL. J., in The Flavonoids-Advances in Research Since 1980, ed. HarborneJ. B., Chapman and Hall, London, 1988, p. 21; and in The Flavonoids-Advances in Research Since 1986, ed. J. B. Harborne, Chapman and Hall, London, 1994, p. 23.
2.
FerreiraD., NelR. J. J., and BekkerR., in Comprehensive Natural Products Chemistry, eds. BartonD., NakanishiK., Elsevier, Oxford, 1999, vol. 3, p. 747.
3.
van RensburgH., van HeerdenP. S., BezuidenhoudtB. C. B., and FerreiraD., Tetrahedron Lett., 1997, 38, 3089.
4.
van RensburgH., van HeerdenP. S., and FerreiraD., J. Chem Soc., Perkin Trans. 1, 1997, 3415.
5.
SharplessK. B., AmbergW., BennaniY. L., CrispinoG. A., HartungJ., JeongK. S., KwongH. L., MorikawaK., WangZ. M., XuD., and ZhangX., J. Org. Chem., 1992, 57, 2768.
6.
KorverO., and WilkinsC. K., Tetrahedron, 1971, 27, 5459.
