-α- and -β- D -erythrofuranosyl)-1- p -tolyl-2 H -imidazole-2-thiones ( 8 and 9 ) were obtained by acid-catalysed dehydration of 1,3-dihydro-3-methyl-4-(4-thio- d - arabino -tetritol-1-yl)-1- p -tolyl-2 H -imidazole-2-thione. The thiol group was introduced in position 4′ of 1,3-dihydro-3-methyl-4-( d - arabino -tetritol-1-yl)-1- p -tolyl-2 H -imidazole-2-thione by selectivetosylation, followed by