title: Intramolecular ionic Diels-Alder reactions of alpha-acetylenic acetals.
abstract: The intramolecular ionic Diels-Alder reaction of alpha-acetylenic acetals as a precursor of the propargyl cation has been investigated in the presence of Lewis acids and in protic acids. The reaction of diene-tethered alpha-acetylenic acetals (1-2) with formic acid yielded the regioselective intramolecular ionic Diels-Alder reaction products, bicyclodienal (9) and bicyclodienone (11) derivatives, in good yields.
authors.affiliation: School of Chemistry, Seoul National University, Seoul 151-742, Korea.
authors.forename: Seung-Bo
authors.initials: SB
authors.lastname: Shim
authors.forename: Yoon-Joo
authors.initials: YJ
authors.lastname: Ko
authors.forename: Byeong-Wook
authors.initials: BW
authors.lastname: Yoo
authors.forename: Chang-Keun
authors.initials: CK
authors.lastname: Lim
authors.forename: Jung-Hyu
authors.initials: JH
authors.lastname: Shin