title: Lewis acid-promoted cyclization of heteroatom-substituted enynes.
abstract: Lewis acid-promoted cyclizations of heteroatom-substituted enynes have been examined. The reaction of enynes and bearing silicon substituents on an alkyne afforded the halogenated five-membered gamma-lactones and gamma-lactams as the main products. The reaction of substrates and having 2-phosphonoacrylate instead of malonate also gave halogenated five-membered cyclic compounds and as the major products. The cyclized products are highly substituted and potentially useful for further synthetic transformations.
authors.affiliation: Department of Chemistry, Nara University of Education, Takabatake-cho, Nara 630-8528, Japan. yamazaks@nara-edu.ac.jp
authors.forename: Shoko
authors.initials: S
authors.lastname: Yamazaki
authors.forename: Kuriko
authors.initials: K
authors.lastname: Yamada
authors.forename: Kagetoshi
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D003500:Cyclization; D007769:Lactams / Q000138:chemical synthesis; D007783:Lactones / Q000138:chemical synthesis
chemical_list: D000480:Alkynes; D002264:Carboxylic Acids; D007769:Lactams; D007783:Lactones