title: Unusual intramolecular bridging reaction in thiacalix[4]arene series.
abstract: Thiacalix[4]arene immobilized in the cone conformation undergoes a direct formylation reaction giving unusual products in high yields. The Duff reaction (urotropine/TFA) leads to unprecedented intramolecularly bridged compounds possessing two formyl groups on the opposite para- or para-/meta-positions. The comparison with the corresponding classical calix[4]arene analogues indicates an amazingly different reactivity of the thiacalix[4]arene system.
authors.affiliation: Department of Organic Chemistry and Laboratory of NMR Spectroscopy, Prague Institute of Chemical Technology, Technicka 6, 166 28 Prague 6, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Kundrat
authors.forename: Hana
authors.initials: H
authors.lastname: Dvorakova
authors.forename: Ivana
authors.initials: I
authors.lastname: Cisarova
authors.forename: Michaela
authors.initials: M
authors.lastname: Pojarova
authors.forename: Pavel
authors.initials: P
authors.lastname: Lhotak