From dipivaloylketene to tetraoxaadamantanes

• Gert Kollenz and
• Curt Wentrup

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

• 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

Enantioselective synthesis of polyhydroxyindolizidinone and quinolizidinone derivatives from a common precursor

• Nemai Saha and
• Shital K. Chattopadhyay

Beilstein J. Org. Chem. 2014, 10, 3104–3110, doi:10.3762/bjoc.10.327

• [29], ring expansion–transannular cyclization [30], Cope–House cyclization [31], etc. as key steps. Although great advances have been made, creation of diverse entities from a single source remains important. Herein, we report a synthetic entry to some polyhydroxylated indolizidine and quinolizidine

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• transannular cyclization of 10 using elemental iodine under air [21]. Dehydrobenzo[12]annulene 10 in turn was synthesized via Glaser homocoupling of 1,2-diethynylbenzene [21][22][23]. While in theory this route permitted relatively easy access to diethynyldiones 8, in practice it was fraught with problems: (1

• . Black lines represent the molecules with circles denoting the centroid. Transannular cyclization route to diethynyl-IF-diones 8. Suzuki/Friedel-Crafts route to diethynyl-IF-diones 8. Diethynyl-IF-diones synthesized and yields for Sonogashira cross-coupling. Electrochemical and optical data for ID-diones