Jj. Reinier,"nel et al., Stereoselective synthesis of flavonoids. Part 8. Free phenolic flavan-3-oldiastereoisomers, J CHEM R-S, (10), 1999, pp. 606-607A
Asymmetric dihydroxylation of a series of poly-O-methoxymethyl-1,3-diarylpr
openes with AD-mix-alpha or AD-mix-beta and subsequent acid-catalyzed cycli
zation of the intermediate syn-diols permits the first synthetic access to
all four diastereoisomers of free phenolic flavan-3-ols in high enantiomeri
c excess and yield.