20110213141METHOD FOR PREPARING 1,6:2,3-DIANHYDRO-BETA-D-MANNOPYRANOSE - The invention relates to a method for preparing 1,6:2,3-dianhydro-??-D-mannopyranose and is characterized in that it includes a step of cyclizing the compound C, where R is an alykyl group and R??? is an activating agent, in an alcohol/alcoholate mixture under anhydrous conditions.09-01-2011