title: Lewis acid-promoted cyclization reactions of alkenyl ethenetricarboxylates: stereoselective synthesis of 2-oxotetrahydrofurans and 2-oxopyrrolidines.
abstract: Lewis acid-promoted intramolecular reactions of alkenyl ethenetricarboxylates and the corresponding amides have been examined. Reaction of allyl ethenetricarboxylates and the amides with Lewis acids (1-2 equiv) such as TiCl4, TiBr4, AlCl3, and AlBr3 gave 3,4-trans-halogenomethyl 2-oxotetrahydrofuran and pyrrolidine derivatives stereoselectively in high yields. The stereochemistries were determined by NOE experiments. Reaction of alkyl-substituted allylic ethenetricarboxylates with Lewis acids gave chloro 2-oxotetrahydrofurans and pyrans. For some alkyl-substituted substrates, cationic intermediates may be formed under the reaction conditions, and rearranged products have been obtained.
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: Ken
authors.initials: K
authors.lastname: Fujinami
authors.forename: Yuki
authors.initials: Y
authors.lastname: Maitoko
authors.forename: Khota
authors.initials: K
authors.lastname: Ueda
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Kakiuchi
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D058116:Lewis Acids / Q000737:chemistry*; D015394:Molecular Structure; D011760:Pyrrolidinones / Q000138:chemical synthesis* / Q000737:chemistry; D011789:Quantum Theory; D013237:Stereoisomerism
chemical_list: D002264:Carboxylic Acids; D005663:Furans; D058116:Lewis Acids; D011760:Pyrrolidinones