title: Lewis acid-catalyzed conjugate addition-cyclization reactions of ethenetricarboxylates with substituted propargyl alcohols: stereoselectivity in the efficient one-pot synthesis of methylenetetrahydrofurans.
abstract: Oxygen-containing heterocyclic systems are important structures in organic chemistry because of their presence in many biologically active compounds. In this work, a Lewis acid-catalyzed cyclization of ethenetricarboxylate derivatives 1 with substituted propargyl alcohols to give methylenetetrahydrofurans was investigated. Reaction of 1 and gamma-silicon-substituted propargyl alcohols 4 with ZnBr2 at 80-110 degrees C led to (Z)-silicon-substituted products stereoselectively. Reaction of 1 and gamma-ester-substituted propargyl alcohol 7 in the presence of various Lewis acids gave ester-substituted methylenetetrahydrofurans stereoselectively. Interesting Lewis acid dependency on stereoselectivity for the reaction of 7 was found. Reaction of alpha-substituted propargyl alcohols also gave cyclized products.
authors.affiliation: Department of Chemistry, Nara University of Education, Takabatake-cho, Nara 630-8528, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morikawa
authors.forename: Shoko
authors.initials: S
authors.lastname: Yamazaki
authors.forename: Momoko
authors.initials: M
authors.lastname: Tsukada
authors.forename: Suguru
authors.initials: S
authors.lastname: Izuhara
authors.forename: Tsumoru
authors.initials: T
authors.lastname: Morimoto
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Kakiuchi
mesh_terms: D000143:Acids / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D005663:Furans / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D020005:Propanols / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
chemical_list: D000143:Acids; D000480:Alkynes; D002264:Carboxylic Acids; D005663:Furans; D020005:Propanols; C028255:propargyl alcohol