Ring opening of 3-oxo-1,2-cyclopropanated sugars with thiols leads to the serendipitous discovery of the synthesis of sugar based homologated acyclic dithioacetals. These acyclic dithioacetals were found to undergo one-pot septanoside formation followed by stereoselective glycosylation in the presence of glycosyl acceptors under glycosylation reaction conditions.

The first total synthesis of a structurally diverse mixed ligand siderophore, gobichelin B produced by Streptomyces sp. NRRL F-4415, is reported. The systematic assembly of the building blocks to synthesize Gob-B 1st half and Gob-B 2nd half and subsequent coupling of these two fragments followed by global deprotection using Pearlman's catalyst led to the isolation of gobichelin B in excellent yield and purity.

The stereoselective synthesis of deoxy C‐glycoside derivatives that have a methylene or methyl group at C‐2 position was investigated by employing the Claisen rearrangement of 2‐vinyloxy methyldeoxy‐glycals as the synthetic precursors. The method proceeded with high diastereoselectivity to afford C‐2‐methylene α‐C‐glycosides. Complementary to this protocol, a ZnII‐mediated anomerization of the α‐C‐glycosides to give the corresponding β‐C‐glycosides was also used to obtain diastereomerically pure C‐2‐methylene β‐C‐glycosides. The generality of the reaction was fully evaluated, and the developed method was successfully applied to the formal stereoselective total synthesis of (–)‐brevisamide, a monocyclic ether alkaloid that was isolated from Karenia brevis (red tide dinoflagellate).

*= corresponding authorsCapsaicin is known to interfere with tight junctions (TJ) of epithelial cells and therefore to enhance paracellular permeability of poorly absorbable drugs. However, due to its low water solubility, pungency and cytotoxicity its pharmacological use is limited. In this study, we investigated the effect of capsaicin derivatives of synthetic ( 10*hydroxy*N*(4*hydroxy*3*methoxybenzyl)decanamide, etc.) and natural (olvanil and dihydrocapsicin) origin on MDCK*C7 cells. Impedance spectroscopy was used to determine the transepithelial electrical resistance and the capacitance. Permeability assays with FITC*dextran were carried out to evaluate the impact on cell permeability. The results show that lipophilicity could play an important role for the interference with TJ and that the mechanism is independent from the ion channel TRPV 1 and hence, on the flux of calcium into the cells. In summary, we synthesized four derivatives of capsaicin of lower lipophilicity and compared their properties with other well*known vanilloids. We show that these compounds are able to enhance the permeability of a hydrophilic macromolecule, by opening the TJ for a shorter time than capsaicin. This behavior is dependent on the lipophilicity of the molecule.

Lewis acid mediated stereoselective synthesis of 2-deoxy-O-glycosides has been demonstrated using 2-deoxyglycosyl 3-benzoylpropionates as novel glycosyl donors. These newly developed donors are easily synthesized from simple glycals, are stable at room temperature and react with ease to provide products with high stereoselectivity. These donors can be successfully utilized with all types of acceptors (primary, secondary and tertiary alcohols) for the synthesis of 2-deoxy-glycosides. Additionally, these newly developed glycosyl donors are also efficient for the synthesis of trisaccharides.