4394-76-7

Upstream product

• 89324-43-6 hexa-2,4-diynoic acid 
• 6214-35-3 (Z)-3-iodoprop-2-enoic acid 
• 53915-69-8 allenyltributylstannane 
• 4426-47-5 butylboronic acid 
• 344340-90-5 5-iodo-6-methyl-2(2H)-pyranone 
• 27751-97-9 4-hydroxy-6-methyl-tetrahydro-2H-pyran-2-one 
• 74252-53-2 6-Methyl-3-phenylsulfanyl-3,4-dihydro-pyran-2-one 
• 74252-52-1 6-Methyl-3-methylsulfanyl-3,4-dihydro-pyran-2-one 
• 74252-47-4 2-methylthio-5-oxohexanoic acid 
• 26922-36-1 6-methoxy-2-methyl-3,6-dihydro-2H-pyran-3-ol 
• 283156-12-7 3-bromo-6-methoxy-2-methyl-3,6-dihydro-2H-pyran 
• 41728-14-7 6-hydroxy-2-methyl-2H-pyran-3(6H)-one 
• 41728-10-3 6-methoxy-2-methyl-2H-pyran-3(6H)-one 
• 283156-16-1 5-bromo-6-methyl-5,6-dihydro-2H-pyran-2-one 

Downstream Products

• 57509-00-9 C₂₅H₂₀N₂O₄ 
• 134593-95-6 6-<(tert-butyldimethylsilyl)oxy>-3-methyl-8-phenyl-4a,5,8,8a-tetrahydro-1H-benzopyran-1-one 
• 119972-66-6 tert-Butyl-dimethyl-(6-methyl-4-p-tolyl-4H-pyran-2-yloxy)-silane 
• 134593-96-7 3-Methyl-8-phenyl-4a,7,8,8a-tetrahydro-5H-isochromene-1,6-dione 
• 134593-93-4 6-methyl-4-<(methoxycarbonyl)phenylmethyl>-3,4-dihydro-2H-pyran-2-one 

Relevant academic research and scientific papers

Mechanistic insights into ring-opening and decarboxylation of 2-pyrones in liquid water and tetrahydrofuran

2-Pyrones, such as triacetic acid lactone, are a promising class of biorenewable platform chemicals that provide access to an array of chemical products and intermediates. We illustrate through the combination of results from experimental studies and first-principle density functional theory calculations that key structural features dictate the mechanisms underlying ring-opening and decarboxylation of 2-pyrones, including the degree of ring saturation, the presence of C=C bonds at the C4=C5 or C5=C6 positions within the ring, as well as the presence of a β-keto group at the C4 position. Our results demonstrate that 2-pyrones undergo a range of reactions unique to their structure, such as retro-Diels-Alder reactions and nucleophilic addition of water. In addition, the reactivity of 2-pyrones and the final products formed is shown to depend on the solvent used and the acidity of the reaction environment. The mechanistic insights obtained here provide guidance for the selective conversion of 2-pyrones to targeted chemicals.

Synthesis of isocoumarins and α-pyrones via tandem Stille reaction/heterocyclization

A general route to α-pyrones and 3-substituted isocoumarins from (Z)-iodovinylic acids 1a-f or 2-iodobenzoic acids 4a-c is described, including compounds bearing a substituent on the aromatic ring. Treatment of (Z)-β-iodovinylic acids 1a-f or 2-iodobenzoic acids 4a-c with various allenyl-tributyltin reagents in the presence of palladium acetate, triphenylphosphine, and tetrabutylammonium bromide in dimethylformamide provided good yields of the corresponding α-pyrones 3a-k or 3-substituted isocoumarins 5a-g via tandem Stille reaction and 6-endo-dig oxacyclization.

Compounds having protected hydroxy groups

The present invention relates to compounds with protected hydroxy groups of formula (I) These compounds are precursors for organoleptic agents, such as fragrances, and masking agents and for antimicrobial agents. When activated, the compounds of formula (I) are cleaved and form one or more organoleptic and/or antimicrobial compounds.

Compounds having protected hydroxy groups

The present invention relates to compounds with protected hydroxy groups of formula (I) These compounds are precursors for organoleptic agents, such as fragrances, and masking agents and for antimicrobial agents. When activated, the compounds of formula (I) are cleaved and form one or more organoleptic and/or antimicrobial compounds.

Selective synthesis of natural and unnatural 5,6-disubstituted 2(2H)-pyranones via iodolactonization of 5-substituted (Z)-2-en-4-ynoic acids

Reaction of 5-substituted (Z)-2-en-4-ynoic acids with iodine and NaHCO3 in CH3CN or with ICl in CH2Cl2 affords mixtures of (E)-5-(1-iodoylidene)-2(5H)-furanones and 6-substituted 5-iodo-2(2H)-pyranones in which these last compounds are the major products. The 5-iodo-2(2H)-pyranones, which are easily separated chromatographically from the corresponding regioisomers, are able to undergo Stille-type reactions with a variety of organotin compounds to give 5,6-disubstituted 2(2H)-pyranones in moderate to good yields. One of these compounds, i.e. 5-(1-butynyl)-2(2H)-pyranone, has been used as direct precursor to two substances produced by fungal culture LL-11G219, which function as androgen ligands, i.e. (Z)-5-(1-butenyl)-6-methyl-2(2H)-pyranone and 5-butyl-6-methyl-2(2H)-pyranone.

Precursor compounds

The compounds of the formula I are precursors for organoleptic and antimicrobial compounds. The latter are generated in the presence of skin bacteria, enzymes or acidic or alkaline conditions. One precursor molecule can provide one or more different compounds.

Beta-ketoester compounds

The beta-ketoesters of formula I are useful as precursors for organoleptic compounds, especially for flavors, fragrances and masking agents and antimicrobial compounds.

Palladium-catalysed annulation reaction of allenyltins with β-iodo vinylic acids: Selective synthesis of α-pyrones

Palladium-catalysed regio- and stereoselective annulation of allenyl stannanes by β-iodo vinylic acids gives the corresponding α-pyrones in high yields. This annulation most probably proceeds through a Stille reaction/cyclisation sequence.

A NEW 2-PYRONE SYNTHESIS AND ITS APPLICATION TO BUFADIENOLIDE SYNTHESIS

A synthetic method of 4-, 5-, and 6-alkyl-2-pyrones from an appropriately substituted α,β-unsaturated ketone or aldehyde was presented.The reaction sequence consisted of 1) conjugate addition of a methylthio- or phenylthioacetate to the enone by use of th