The Lewis acid-catalyzed cyclocondensation of methylthio (or phenylthio)-silyloxydienes (2), easily derived from stable sulfur ylides (1), with several aromatic aldehydes (3) was investigated. Namely, in the case of boron trifluoride normal reaction products, 2,3-dihydro-4-pyrones (4), were obtained in good yields. Novel reaction products, thiolanium ylides (6 and 7), were obtained in the presence of titanium(IV) chloride. The structures of 6g was established by X-ray crystallography.
All Science Journal Classification (ASJC) codes
- 化学 (全般)