The stereospecific formation of alpha-D-mannosyl glycosidic linkages has been achieved in high yield using tetra-O-pivaloyl-alpha-D-mannopyranosyl fluoride and boron trifluoride diethyl etherate in dichloromethane. Examples of the alpha-D-mannosylation of primary, secondary, benzylic and phenolic hydroxyl groups are described. (C) 1999 Elsevier Science Ltd. All rights reserved.
VO(acac)2/H2O2/NaI: a mild and efficient combination for the cleavage of dithioacetal derivatives of sugars
摘要:
A wide variety of dithioacetal derivatives of sugars can be cleaved easily into the corresponding open-chain aldehydo sugars using an efficient combination of VO(acac)(2)/H2O2/NaI at 0-5 degrees C. Some of the salient features of this protocol are mild reaction conditions, good yields, short reaction times, easy work-up procedures, and non-involvement of toxic chemicals. (C) 2011 Elsevier Ltd. All rights reserved.
This invention features methods and compositions for delivery of nucleic acids (e.g., DNA, RNA, PNA, and hybrids thereof) to cells. The nucleic acid delivery complexes of the invention permit biologically active nucleic acids to be delivered to cells and organisms in vitro and in vivo in a manner and form that allows the nucleic acids to carry out their desired biological function.
The present invention relates to a liquid crystal compound that can be used as a base for injection formulations. The present invention provides an amphipathic compound having the following general formula (I):
wherein X and Y each denotes a hydrogen atom or together denote an oxygen atom, n denotes an integer from 0 to 2, m denotes the integer 1 or 2, and R denotes a hydrophilic group generated by removal of one hydroxyl group from any one selected from the group consisting of glycerol, erythritol, pentaerythritol, diglycerol, triglycerol, xylose, sorbitol, ascorbic acid, glucose, galactose, mannose, dipentaerythritol, maltose, mannitol, and xylitol; as well as a base for injection formulations and depot formulation comprising the same.
A process for the preparation of a thiosaccharide represented by Saccharide-S-H wherein Saccharide comprises at least 4 sugar units, comprises subjecting a corresponding compound of the formula (P)Saccharide-S-(P) wherein (P) represents an O- or S-protecting group(s), to Birch reduction.
Prebiotic carbohydrate synthesis: zinc–proline catalyzes direct aqueous aldol reactions of α-hydroxy aldehydes and ketones
作者:Jacob Kofoed、Jean-Louis Reymond、Tamis Darbre
DOI:10.1039/b501512j
日期:——
Znâproline catalyzed aldolisation of glycoladehyde gave mainly tetroses whereas in the cross-aldolisation of glycoladehyde and rac-glyceraldehyde, pentoses accounted for 60% of the sugars formed with 20% of ribose.