110512-33-9Relevant articles and documents
Formation of bicyclic β-lactams from dichloro-1,4-oxathiane-3- carboxanilides: Nucleophilic substitution of nitrogen on anomeric carbon
Hahn, Hoh-Gyu,Chang, Kee-Hyuk
, p. 713 - 719 (2007/10/03)
Transformation of dichloro-1,4-oxathiane anilides (2) to bicyclic β- lactam (5) is described. In the presence of sodium hydride, an intramolecular nucleophilic substitution of nitrogen to anomeric carbon of 2 gave (1R*, 6R*)-1-chloro-6-methyl-7-phenyl-5-oxa-2-thia-7-azabicyclo[4,2,0]octan-8-ones (5). The reason for facile displacement at C-2 is attributable to neighboring group participation of sulfur and C-2 is anomeric. Plausible mechanisms for the formation of 2-chloromethyl-5,6-dihydro-N-phenyl-1,4-oxathiin-3- carboxyamide (4) under the neutral conditions, or 2,3-dihydroxy-2-methyl-N- phenyl-1,4-oxathiane-3, carboxyamide (9) in aqueous solution, or bicyclic β- lactam (5) in the presence of sodium hydride were proposed.
Synthesis of Dihydro-1,4-oxathiins by Action of Chlorine on 1,3-Oxathiolanes
Lee, Wha Suk,Park, Oee Sook,Choi, Joong Kwon,Nam, Kee Dal
, p. 5374 - 5377 (2007/10/02)
A new convenient synthesis of 5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxylic acid derivatives 1 has been achieved by using the action of chlorine on 2-methyl-N-phenyl-1,3-oxathiolane-2-acetamide (4a) and 2-methyl-1,3-oxathiolane-2-acetic acid methyl ester (4b).From the initially formed chlorosulfonium salts 16 unobserved transient sulfenyl chlorides 5 were generated, followed by cyclization to probable oxonium ion 18 to produce dihydrooxathiins 1.In the chlorinolysis reactions of 4a and 4b minor byproducts were formed: respectively 2,3-dichloro-2-methyl-1,4-oxathiin-3-carboxanilide 12a and its methyl ester analogue 12b.While 12b was stable, 12a was unstable, transforming to the corresponding 2-chloromethyl compound 13.The mechanism of formation of 13 as well as relative stability of dichlorides 12a, 12b, and related compounds is also discussed.