76311-89-2Relevant articles and documents
3-Bromo-2,5-dihydrofuran-2-one and 4-bromo-2,5-dihydrofuran-2-one
Brecker, Lothar,Kreiser, Wolfgang,Ernst, Ludger,Hopf, Henning
, p. 1154 - 1158 (1999)
Although 3-bromo-2,5-dihydrofuran-2-one and 4-bromo-2,5-dihydrofuran-2-one were first reported in 1894, considerable ambiguity still exists about the correct structure assignment of the two compounds. The present article gives a brief overview on the varying assignments of constitution and describes a novel method for the formation of 3-bromo-2,5-dihydrofuran-2-one. A comparison is made of the experimental 13C NMR chemical shifts with values predicted by increment calculations and experimental 1/C-C coupling constants are given for both compounds. Secure structural assignments are now available for both isomers.
Controlling the Substitution Pattern of Hexasubstituted Naphthalenes by Aryne/Siloxyfuran Diels–Alder Additions: Regio- and Stereocontrolled Synthesis of Arizonin C1 Analogs
Neumeyer, Markus,Kopp, Julia,Brückner, Reinhard
, p. 2883 - 2915 (2017/06/06)
3,4-Dimethoxybenz-1-yne and 2-siloxylated furans without or with a bromine atom at C-3 undergo Diels–Alder reactions with orientational selectivity. Hydrolysis furnished a bromine-free or a bromine-containing naphthalene, respectively. Bromination of the former provided a regioisomer of the latter. Either of the two compounds was processed to give a variety of unnatural naphthoquinonopyrano-γ-lactones. This occurred by a succession of (1) Heck coupling, (2) asymmetric dihydroxylation, (3) oxa-Pictet–Spengler cyclization, and (4) oxidation. The fifteen monomeric naphthoquinonopyrano-γ-lactone structures that we prepared resemble the natural product (–)-arizonin C1 or its C-5 epimer. Accordingly, they represent hexasubstituted naphthalenes likewise. The sixteenth naphthoquinonopyrano-γ-lactone that we synthesized is a kind of dimer. Its moieties are bridged differently than those in naturally occurring naphthoquinonopyrano-γ-lactone dimers.
Isotope-labeled methyl ketofuran, intermediate and method for preparing same
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Paragraph 0099; 0100; 0101, (2016/10/09)
The invention discloses isotopically labeled methyl furanone, an intermediate and a preparation method of isotopically labeled methyl furanone. The invention provides isotopically labeled methyl furanone 6. The invention further provides a preparation method of isotopically labeled methyl furanone 6, and the preparation method comprises the following steps: performing removal of a hydroxy protecting group and isomerization reaction on a compound 20 in the presence of an acid. The method provided by the invention comprises short reaction steps, labeling loci are stable, are labeled on a common D ring of a strigolactone type compound family and are successfully butted with ABC rings of strigolactone type compounds to obtain a variety of isotopically labeled strigolactone type compounds with different isotopic abundances which are more than 99% respectively, and the isotopically labeled methyl furanone is applicable to wide substances, is used as an internal source standard matter for GC-MS and LC-MS/MS analysis and has high detection sensitivity and good accuracy, thereby having broad market application prospects.