Alkylation of thiohydantoins including synthesis, conformational and configurational studies of some acetylated S-pyranosides

5-Benzylidene-2-thiohydantoin (1) and 5,5-dimethyl-2,4-dithiohydantoin (6) undergo Mannich reaction with formaldehyde and morpholine to give the corresponding Mannich products 2 and 7, respectively. Subsequent reaction of the product 2 and 7 with phenacyl bromide gives the corresponding 2-benzolmethylthiohydantoin Reactionof 5-benzylidene-2-carbomethoxythiohydantoin (5b) with P2S5 afforded 4-benzylideneimidazo[2,1-b]-thiazole-2-thione-5-one (13) as the sole product. Reaction of 2-thio and 2,4-dithiohydantoin derivatives 2 and 7 with (2,3,4,6-tetra-O-acetyl-alpha-D-gluco- or galgcto- pyranosyl) bromide or (2,3,4-tri-O-acetyl-alpha-xylopyranosyl) bromide afforded the corresponding S-gluco- galacto- or xylosides (14-19). Many attempts to deacetylation of the resulting S-nucleosides and to get N-nucleosides were tried.