title: Synthesis of 2-alkyl- and 2-carboxy-p-tert-butylcalix[4]arenes via the lithiation of tetramethoxy-p-tert-butylcalix[4]arene.
abstract: [reaction: see text]. Tetramethoxy-p-tert-butylcalix[4]arene reacts readily with n-butyllithium to give a putative monolithiated intermediate that is substituted with alkyl halides and carbon dioxide to give in 60-75% yield conformationally mobile calix[4]arenes monosubstituted at the methylene bridge (2-position). 2-Alkyl- and 2-benzyl-substituted tetramethoxycalix[4]arenes are converted in 62-68% overall yield to the corresponding tetrahydroxy-p-tert-butylcalix[4]arenes by treatment with boron tribromide. The tetrahydroxy-p-tert-butylcalix[4]arenes exist in the cone conformation at room temperature in CDCl3 as judged by NMR spectroscopy.
authors.affiliation: Department of Chemistry and Biochemistry, Ebaugh Laboratories, Denison University, Granville, Ohio 43023, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Scully
authors.forename: T M
authors.initials: TM
authors.lastname: Hamilton
authors.forename: J L
authors.initials: JL
authors.lastname: Bennett