The isolation of 3-methyl-8-oxa-3-azabicyclo [3.2. l] octane methobromide (VI, R= CH3)(50%) from the product ob-tained from dimethylamine and cis-2, 5-bis-(hydroxymethyl)- tetrahydrofuran ditosylate (I) demonstrates the existence of the corresponding quaternary tosylate (11, R= CHa) in the initial reaction mixture. The reaction also yields a significant amount of trimethylamine, formed by alkylation of dimethylamine by the quaternary ...