19978-32-6

Usage

Synthesis Reference(s)

Organic Syntheses, Coll. Vol. 9, p. 112, 1998The Journal of Organic Chemistry, 34, p. 2239, 1969 DOI: 10.1021/jo01260a001

Upstream product

• 504-31-4 pyran-2-one 
• 3040-20-8 2-pyrone-3-carboxylic acid 
• 137776-72-8 3,5-dibromo-5,6-dihydro-2H-pyran-2-one 
• 3393-45-1 5,6-dihydro-pyran-2-one 
• 53646-72-3 5-bromo-5,6-dihydro-2H-pyran-2-one 
• 60249-17-4 6-methoxy-2H-pyran-3(6H)-one 
• 108-48-5 2,6-dimethylpyridine 
• 69739-34-0 t-butyldimethylsiyl triflate 
• 500-05-0 2H-pyran-2-one-5-carboxylic acid 
• 104184-64-7 3-Bromo-5,6-dihydro-2H-pyran-2-one 
• 283156-10-5 3-bromo-6-methoxy-3,6-dihydro-2H-pyran 
• 283156-05-8 methyl 2,3-dideoxy-α,β-DL-glycero-pent-2-enopyranoside 
• 35436-57-8 6-hydroxy-3,6-dihydro-2H-pyran-3-one 
• 283156-19-4 3,4,5-tribromo-3,4,5,6-tetrahydro-2H-pyran-2-one 

Downstream Products

• 98061-54-2 3-(p-tolylthio)-2-pyrone 
• 31678-73-6 3-methyl-2H-pyran-2-one 
• 504-31-4 pyran-2-one 
• 99268-86-7 (+/-)-3-p-toluenesulfinyl-2-pyrone 

Relevant academic research and scientific papers

AN ORGANOMETALLIC ROUTE TO (+/-)-3-p-TOLUENESULFINYL-2-PYRONE

3-Bromo-2-pyrone reacts with dimethylcopperlithium and then with p-tolyl p-toluenethiosulfonate to form 3-p-toluenethio-2-pyrone.Organocopper species are likely intermediates in this reaction.Oxidation of the sulfide produces (+/-)-3-p-toluenesulfinyl-2-pyrone.The overall process involves an important and useful umpolung, a reversal of reactivity at C(3) of the pyrone ring from an electrophilic center to a nucleophilic center.

3-Bromo-2-Pyrone: An Alternative and Convenient Route to Functionalized Phosphinines

The facile access to 3-bromo-2-pyrone allows the preparation of 6-bromo-2-trimethylsilyl-phosphinine by a [4+2] cycloaddition with Me3Si-C≡P for the first time. The regioselectivity of this reaction could be verified by means of single crystal X-ray diffraction of the corresponding W0complex. In the presence of ZnBr2and dppp (1,3-bis(diphenylphosphino)propane) as a bidentate ligand, the bromo-phosphinine quantitatively undergoes a Negishi cross-coupling reaction with PhLi that selectively leads to 6-phenyl-2-trimethylsilyl-phosphinine. This heterocycle could again be characterized by means of X-ray diffraction as a W0complex. These results describe a new and convenient route to 2,6-disubstituted phosphinines that makes use of readily available starting materials.

One step preparation of bromo-2-pyrones via bromo-decarboxylation of 2-pyrone-carboxylic acids

Synthetically valuable 3-bromo-2-pyrone, 3-bromocoumarin, 5-bromo-2-pyrone, and 3,5-dibromo-2-pyrone were prepared in one step from readily available 2-pyrone-carboxylic acids via bromo-decarboxylation in good to fair yiels.

Modified Nucleosides for Rna Interference

The present invention relates to the use of modified nucleotides and single or double stranded oligonucleotides having at least one of said modified nucleotides for performing RNA interference. The modified nucleotides are selected from 6-membered ring containing nucleotides such as hexitol, altritol, O-substituted or O-alkylated altritol, cyclohexenyl, ribo-cyclohexenyl and O-substituted or O-alkylated ribo-cyclohexenyl nucleotides. The present invention also relates to novel modified nucleosides or nucleotides and to the use of the novel modified nucleosides and nucleotides in single or double stranded oligonucleotides for RNA interference, antisense therapy or other applications.

Synthesis and conformational analysis of a ribo-type cyclohexenyl nucleoside

A straightforward approach to a novel class of ribo-type cyclohexenyl nucleosides is described. An electron-demand Diels-Alder reaction forms the key-step of the chosen synthetic pathway. Although the difference is small, conformational analysis using NMR shows that this nucleoside analogue adopts preferentially an 2H3 conformation (S-type), while the "deoxy" cyclohexenyl analogue has a preference for a C3′ endo conformation (N-type). Analyses of the conformational equilibrium reveal that, in the given experimental conditions, the difference between adenosine and its cyclohexenyl congener resides in their different ΔG values; furthermore, in adenosine, the conformational preference is of enthalpic origin, whereas in the cyclohexenyl congener, the conformational preference is of entropic origin.

Antiproliferative hybrid analogs of the hormone 1α,25-dihydroxyvitamin D3: Design, synthesis, and preliminary biological evaluation

The combination of 10-12 kbar pressure plus Lewis acidic zinc dichloride promotes highly regioselective and stereoselective Diels-Alder cycloaddition between 3-bromo-2-pyrone, prepared in a new way, and unactivated terminal alkene 4-(tert-butyldimethylsiloxy)-1-butene. The conjugate base of A-ring allylic phosphine oxide 20 adds chemospecifically to the C-8 keto group of some C-8,C-24-diketones to form directly metabolically resistant 24-oxo analogs of 1α,25-dihydroxyvitamin D3 (calcitriol). Several of these new hybrid analogs are as efficacious in vitro as calcitriol at inhibiting growth of murine keratinocytes even at physiologically relevant 10-100 nanomolar concentrations.

Vitamin D3 analogues

A vitamin D3 analogue which includes a hydroxyalkyl substituent in the 1-position and a modified D-ring side chain is described. This novel compound is a potent anti-proliferative substance with activity comparable to that of calcitriol but with a vitamin D3 receptor binding rating of approximately 10-3 compared to that of calcitriol.

3-BROMO-2-PYRONE: AN EASILY PREPARED CHAMELEON DIENE AND A SYNTHETIC EQUIVALENT OF 2-PYRONE IN THERMAL DIELS-ALDER CYCLOADDITIONS

3-Bromo-2-pyrone, a stable solid prepared by a new route (eq. 1), has been found to undergo smooth and regiospecific 2+4-cycloadditions between 78-90 deg C with both electron-rich and electron-deficient dienophiles; subsequent high-yield reductive debromi