42506-10-5Relevant articles and documents
Synthesis of six- to nine-membered ring oximinoorthodithiolactones by cyclization of nitroketene S,S-acetals in trifluoromethanesulfonic acid
Coustard, Jean-Marie
, p. 1525 - 1531 (2007/10/03)
2-Nitro-1,1-bis(phenylalkylthio)ethene or 1-(methylthio)-2-nitro-1-(phenylalkylthio)ethene derivatives tethered to an aromatic ring undergo a fast intramolecular cyclization in trifluoromethanesulfonic acid, with the intermediate formation of dications, which can be detected by NMR spectroscopy. Quenching with methanol at low temperature affords cyclic orthothioesters of isothiochromanones, 4,5-dihydrobenzo[d]-thiepin-1-one, 5,6-dihydro-4H-benzo[d]thiocin-1-one and 8,9,10,11-tetrahydro-7-thiabenzocyclononen-5-one oximes. The yields are usually fair to good, except for the nine-membered ring derivatives.