synthesis of the new triterpenes involved three linear steps starting from readily available 3-O-acetyl-betulinal: elongation of the carbon chain by Wittig reaction followed by enol ether hydrolysis and reduction (or oxidation) of the elongated aldehyde. Saponins were obtained by glycosylation of triterpenes with classical Schmidt donors. Cytotoxic activities of new lupane and homolupane compounds were evaluated
practical method for the preparation of benzoyl protected allyl and benzyl α-D-idopyranosides, and D-idopyranosyl trichloroacetimidate, from 1,2,3,4,6-penta-O-acetyl-α-D-idopyranose, is described. All derivatives can be prepared on a multigram scale and require only simple chromatographic purification. A concisesynthesis of lupane triterpenes bearing an unusual D-idopyranoside fragment is described. All
Synthesis of lupane bidesmosides was optimized. The title compounds were obtained by glycosylation of 3-O- or 28-O-substituted betulin monodesmosides with Schmidt donors catalyzed by TMSOTf. Classical batch procedure and microreactor technique were used and compared in the above synthesis. Experimental results clearly showed that both methods are comparable, although any particular outcome strongly