Anhydro Sugar Formation in Acid and Base Hydrolyses of 3,4-Di-O-methylsulfonyl-D-mannitol: a Rapid Route to 1,4:3,6-Dianhydro-D-iditol(D-Isoidide)

Abstract

. Can. J. Chem. 52,3367(1974). Brief acid hydrolysis of 1,2: 5,6-di-O-isopropylidene-3,4-di-O-methyls~1lfonyl-~-n1a1initol (la), removes the isopropylidene groups giving the disulfonated hexitol, 2a. Upon continued acid hydrolysis of 2a, one sulfonate group is lost with formation of a sulfonated monoanhydro hexitol, 5a, then the second ester group is lost to give 1.4: 3,6-dianhydro-D-iditol (D-isoidide, 3a). If the disulfonate, 2a, is treated with base, a n isomeric dianhydro hexitol, the bisoxirane 4, is formed. Under similar basic conditions, the monoanhydro hexitol, 50. is stable. On acid hydrolysis, the bisoxirane, 4, gives hexitols and only 20% of D-isoidide. which indicates that 4 cannot be an intermediate in the conversion of 2a to 30. These results indicate that, in 2a a t least, five-membered anhydro rings are formed preferentially in acid hydrolyses and threemembered rings in saponification.

A Facile and General Synthesis of Rare l-Sugar Lactones

“…It should be noted that the acid-catalyzed displacement of mesyl groups under similar conditions to form furans has been noted before. 7 The intramolecular base-catalyzed displacement of mesyl groups to form ethers is the norm.…”