Preost-Woodward hydroxylation of 2 gave the 22S,23S-glycol(3),contrary to expectation.It is suggested that the formation of the two possibleiodonium ions(4a and
Three polysaccharides TAA,TAB and TAC were purified from the pollen of Typha An-gustifilia L..TAA is mainly composed of α-L-arabinofuranose,β—D—galactose an