[reaction: see text] A zirconocene-mediated ring contraction of 4-vinylfuranosides generated either from d-arabinose or d-glucose is followed by sequential oxidation to the ketone and alkynyl Grignard addition. The resulting cis-cyclobutanediols are subjected in turn to thermal rearrangement and intramolecular oxymercuration-demercuration. The regiochemistry of the final ring closure is controlled by the nature of R.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ol027336t | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Low-Valent Zirconocene-Mediated Synthesis of Porphyrin(2.1.2.1)s and Its Extension to Synthesis of a Porphyrin(2.1.2.1) Nanobarrel.
Angew Chem Int Ed Engl
May 2022
Key Laboratory of Chemical Biology and Traditional Chinese Medicine, Ministry of Educational of China, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, China.
Rosenthal's-reagent-mediated intramolecular cyclometallation of α,α-dialkynyldipyrrin nickel(II) complex and subsequent acid treatment afforded a 1,3-butadiene-embedded porphyrin(2.1.2.
View Article and Find Full Text PDFStereoselective synthesis of the butyrolactone and the oxazoline/furan fragment of leupyrrin A(1).
Org Lett
June 2013
University of Bonn, Kekule-Intitute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany.
Stereoselective syntheses of the Northern and the Southern fragments 2 and 3 of leupyrrin A1 are reported. The convergent preparation of 2 is highlighted by a zirconocene-mediated one-pot cyclization-regioselective opening of an advanced diyne while the route to 3 involves a Krische allylation and a one-pot Sharpless dihydroxylation-cyclization. Comparison of the spectroscopic data with those reported for the natural product supports a relative stereochemical assignment within these heterocycles.
View Article and Find Full Text PDFAssembly of macrocycles by zirconocene-mediated, reversible carbon-carbon bond formation.
Acc Chem Res
June 2011
Department of Chemistry, University of California, Berkeley, 94720-1460, United States.
Macrocyclic compounds have attracted considerable attention in numerous applications, including host-guest chemistry, chemical sensing, catalysis, and materials science. A major obstacle, however, is the limited number of convenient, versatile, and high-yielding synthetic routes to functionalized macrocycles. Macrocyclic compounds have been typically synthesized by ring-closing or condensation reactions, but many of these procedures produce mixtures of oligomers and cyclic compounds.
View Article and Find Full Text PDFThe carbohydrate-sesquiterpene interface. directed synthetic routes to both (+)- and (-)-fomannosin from D-glucose.
J Org Chem
June 2008
Evans Chemical Laboratories, The Ohio State University, Columbus, OH 43210-1185, USA.
An enantiodivergent strategy for the total chemical synthesis of both naturally occurring (+)-fomannosin (1) and its (-)-antipode (ent-1) from alpha-D-glucose has been developed and successfully implemented. The key steps in the overall pathway include the following: (i) application of the zirconocene-mediated ring contraction of vinyl furanosides for the construction of highly substituted cyclobutanols; (ii) the use of ring-closing metathesis to form the pendant five-membered ring; (iii) making recourse to a monothio malonic ester to allow for chemoselective reduction to sensitive lactone intermediate 45; (iv) hydroxyl-directed dihydroxylation with OsO(4) to generate 48; and (v) sequential elimination via a cyclic sulfite and a cyclobutyl triflate. The bridge between the enantiomeric series consisted of a six-step linkup involving the structural modification of 22 so as to generate ent-30b.
View Article and Find Full Text PDFIn pursuit of pestalotiopsin a via zirconocene-mediated ring contraction.
Org Lett
May 2006
Evans Chemical Laboratories, The Ohio State University, Columbus, 43210, USA.
[reaction: see text] An asymmetric route from the epimeric beta-hydroxy esters 4 and 5 to the densely functionalized (+)-10 and (-)-10, respectively, is described. Either cyclobutanol can be made available as the predominant product. The levorotatory antipode has been transformed into the advanced intermediate 21 bearing side chains destined to become incorporated into the cyclononene ring of the title compound (1).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!