From dipivaloylketene to tetraoxaadamantanes

• Gert Kollenz and
• Curt Wentrup

Beilstein J. Org. Chem. 2018, 14, 1–10, doi:10.3762/bjoc.14.1

• Gert Kollenz Curt Wentrup Institute of Chemistry, Karl-Franzens University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia 10.3762/bjoc.14.1 Abstract Dipivaloylketene (2) is

• bisdioxine and tetraoxaadamantane formation are discussed. Keywords: bisdioxines; dipivaloylketene; tetraoxaadamantanes; transannular cyclization; Introduction The tetraoxaadamantane ring system is relatively unknown and no functional group derivatives had been reported prior to our work. The first methyl

• unusual reaction steps: (i) the conversion of the dimer 3 of dipivaloylketene (2) to bisdioxines (2,6,9-trioxabicyclo[3.3.1]nona-3,7-dienes) 4, by the addition of nucleophiles, and (ii) the facile acid-catalyzed hydrolysis of 4 with concomitant transannular cyclization. Following this route a wide variety

Molecular cleft or tweezer compounds derived from trioxabicyclo[3.3.1]nonadiene diisocyanate and diacid dichloride

• Gert Kollenz,
• Ralf Smounig,
• Ferdinand Belaj,
• David Kvaskoff and
• Curt Wentrup

Beilstein J. Org. Chem. 2015, 11, 1–8, doi:10.3762/bjoc.11.1

• unique 2,6,9-trioxabicyclo[3.3.1]nonadiene (“bisdioxine”) system, including the diacid, the diacid dichloride 2 [2] and the diethyl ester 3 [3] are readily synthesized from the stable dimer of dipivaloylketene. DFT calculations at the B3LYP/6-31G** level predict that molecules of this type can exist only

Synthesis of functionalized macrocyclic derivatives of trioxabicyclo[3.3.0]nonadiene

• Sabine Leber,
• Gert Kollenz and
• Curt Wentrup

Beilstein J. Org. Chem. 2012, 8, 738–743, doi:10.3762/bjoc.8.83

• concave, axially chiral [1], bridged bisdioxine diacid dichloride 3 is obtained by acid hydrolysis and subsequent chlorination of the surprisingly stable α-oxoketene 2, itself obtained by dimerization of dipivaloylketene (1) (Scheme 1) [2][3]. The concave structure of 3 and its derivatives together with

• dipivaloylketene (1), which slowly dimerizes to the dimeric oxoketene 2 at room temperature [2][3]. Hydrolysis and subsequent chlorination with thionyl chloride afforded the bisdioxine diacid dichloride 3 [3]. 4,4’-(2-Nitro-1,4-phenylene)bis(4-oxabutanol) (7): Diol 6 was prepared according to the literature [18