It is an object of the present invention is to provide a method of preparing 4-deoxy-D-mannose from widely available raw material selectively in a high yield. The method of the present invention comprises reducing a carbonyl group of the 2-position of levoglucosenone to convert to a hydroxyl group, adding an iodo-group to a double bond at the 4-position and an acyloxy group to the 3-position of levoglucosenone respectively, keeping a trans stereochemical relationship, forming a 1,6-anyhydro-4-deoxy-β-D-mannopyranose derivative having a deoxy from at the 4-position as the result of radical reduction of an iodo-group. The present invention make it possible to prepare a hard-obtaining rare sugar 4-deoxy-D-mannose in a high yield from starting levoglucosenone through a fewer processes than that of a convenient method including a reduction of a carbonyl group of levoglucosenone, an stereoselective addition reaction of an iodo-group and an acyloxy group to a double bond. Owning to this method, 4-deoxy-D-mannose used as not only a constitutional unit of useful sugar compounds including a sugar chain but also as a synthetic raw material can be readily supplied.
The present invention relates to the regeneration of a supported molybdenum catalyst which has been used for the epimerisation of a saccharide. The preferred epimerisation is the conversion of glucose to mannose. The catalyst is regenerated by using an oxidising agent such as a peroxide. The regeneration step can be repeated several times. A further extension of the useful lifetime of the catalyst is obtained by including one or more washing steps.
Compounds of formula (I) or formula (II), compositions and methods useful for treating and/or preventing a fungal infections are provided. wherein the substituents are as defined in the appended claims.