Synthesis of Chiral Pyrrolo[1,2-c]thiazoles via Intramolecular Dipolar Cycloaddition of Münchnones: An Interesting Rearrangement to Pyrrolo[1,2-c]thiazines

• Autor(a) principal: Melo, Teresa M. V. D. Pinho e
• Data de Publicação: 2002
• Outros Autores: Soares, Maria I. L., Gonsalves, António M. d'A. Rocha, Paixão, José A., Beja, Ana M., Silva, Manuela Ramos, Veiga, Luiz Alte da, Pessoa, João Costa
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/10281; https://doi.org/10.1021/jo010807p

Intramolecular dipolar cycloaddition of bicyclic münchnones, 5H,7H-thiazolo[3,4-c]oxazol-4-ium-1-olates, derived from cyclodehydration of 2-substituted-N-acylthiazolidine-4-carboxylic acids are reported. A range of new pyrrolo[1,2-c]thiazole derivatives (7, 14, 15, 20, 23, and 26) were obtained as single enantiomers from 2-phenylthiazolidines, 2-benzoylthiazolidines, and 2-methylthiazolidine-4-carboxylates. Pyrrolo[1,2-c][1,4]thiazine derivative 27 was also obtained from pyrrolo[1,2-c]thiazole derivative 26. The structures of methyl (2R,4R)-2-(p-methoxybenzoyl)thiazolidine-4-carboxylate (17a), methyl (2R,4R)-2-(p-methoxybenzoyl)-N-(prop-2-ynyloxyacetyl)thiazolidine- 4-carboxylate (18), and 3-oxo-4-phenyl-3,4,6,8-tetrahydro-1H-furo[3‘,4‘:2,3]pyrrolo[1,2-c][1,4]thiazine (27) were determined by X-ray crystallography. Chirooptical studies of the pyrrolo[1,2-c]thiazoles were done by confirming the absolute configuration at the chiral center C-3.