Iodine addition, levoglucosenone

Addition of iodine to levoglucosenone has been conveniently performed by the treatment of this enone with a solution of iodine in anhydrous pyridine (17), resulting in the formation of 3-iodolevoglucosenone in moderate (55%) yield. 

Similar functionalization, but at the C-3 position in levoglucosenone, via iodine addition to the conjugate position and then nucleophilic displacement of iodine with a reactive thiol represents another valuable stereoselective strategy to a/p (l-3)-linked 5>thiodisaccharides. 

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