Aqueous base induced selective transformations of 3-(2-oxoalkyl) thiazolium cations
摘要:
The title compounds react with aqueous sodium hydroxide (i) 2%, 1 equiv., (ii) 2%, 2 equiv., and (iii) 8%, 2 equiv., to give 2-hydroxy-2-alkyl/aryl-4-formyl-2, 3-dihydro- 1, 4-thiazines (7), 2-alkyl/aryl-4-formyl-1, 4-thiazines (8) and 2-aroylthiazoles (9), respectively. 7 and 8 with 8% aqueous sodium hydroxide form 9, but 7 with 2% aqueous sodium hydroxide or TFA give 8.
Aqueous base induced selective transformations of 3-(2-oxoalkyl) thiazolium cations
摘要:
The title compounds react with aqueous sodium hydroxide (i) 2%, 1 equiv., (ii) 2%, 2 equiv., and (iii) 8%, 2 equiv., to give 2-hydroxy-2-alkyl/aryl-4-formyl-2, 3-dihydro- 1, 4-thiazines (7), 2-alkyl/aryl-4-formyl-1, 4-thiazines (8) and 2-aroylthiazoles (9), respectively. 7 and 8 with 8% aqueous sodium hydroxide form 9, but 7 with 2% aqueous sodium hydroxide or TFA give 8.
On the intramolecular cyclization of a thiazolium salt
作者:Michael B. Doughty、David S. Lawrence
DOI:10.1039/c39850000454
日期:——
3-Acetonyl-4-methyl-1,3-thiazolium chloride is resistant to basic hydrolysis to its free-thiol form and undergoes instead a unique intramolecularcyclization to yield a stable bicyclic form.