127900-50-9Relevant academic research and scientific papers
Cyclization of Alkynecarboxylic Acids: Synthesis and Reactions of 6-Methylene-1,4-oxathian-2-ones and Their 4,4-Dioxides
Yamamoto, Makoto,Munakata, Hiroshi,Hussein, Mohammed Zaki,Kohmoto, Shigeo,Yamada, Kazutoshi
, p. 279 - 296 (2007/10/02)
In the presence of mercury(II) oxide, (2-propynylthio)acetic acids (3a)-(3e) cyclised to 6-methylene-1,4-oxathian-2-ones (8a)-(8e) in moderate yields.Similarly, (2-propynylsulfonyl)acetic acids (6a)-(6e) also gave 6-methylene-2-oxo-1,4-oxathiane 4,4-dioxides (9a)-(9e).Treatment of oxathian-2-one (8a) and its -4,4-dioxide (9a) with p-toluenesulfonic acid in refluxing benzene gave isomerised products (11a) and (12a) respectively.However, treatment of (8a) and (9a) with p-toluenesulfonic acid in refluxing methanol did not give cyclic adducts (13a) and (14a) but instead good yields of ring-opened methyl esters (15a) and (16a).
