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The three-component reaction of (R)- or (S)-1-phenylethylamine (6), formaldehyde, and an α-(hydroxyimino) ketone 5, i.e., 3-(hydroxyimino)butan-2-one (5a) or 2-(hydroxyimino)-1,2-diphenylethanone (5b), yields the corresponding enantiomerically pure 1-(1-phenylethyl)-1H-imidazole 3-oxide 7 in high yield (Schemes 4;2 and 3). The reactions are carried out either in MeOH or in AcOH. Smooth transformations of the N-oxides into optically active 1-(1-phenylethyl)-1H-imidazoles 10 and 2,3-dihydro-1-(1-phenylethyl)-1H-imidazole-2-thiones 11 are achieved by treatment of 7 with Raney-Ni and 2,2,4,4-tetramethyl-3-thioxocyclobutanone (12), respectively (Scheme 4;4). [ABSTRACT FROM AUTHOR]

Abstract The crystal structures of dimethyl 2,2,4,4-tetramethyl-3-oxocyclobutane-1-spiro-5'-3',4'-diphenyl-(1,3)-thiazolidine-2',2'-dicarboxylate, C26H29NO5S for V, and dimethyl 3,4-diphenyl-5-isopropylidene-(1,3)-thiazolidine-2,2-dicarboxylate, C22H23NO4S for VI, have been solved. The 1,3-thiazolidine ring of compound V has got twisted conformation, while in compound VI this ring adopts envelope. In both structures short inter- and intramolecular contacts were found, which can be recognized as hydrogen bonds. [ABSTRACT FROM AUTHOR]