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Upstream product

• 873-66-5 1-propenylbenzene 
• 64-19-7 acetic acid 
• 75-07-0 acetaldehyde 
• 4192-77-2 ethyl cinnamate 
• 123-63-7 paracetaldehyde 
• 67279-69-0 trans-4,5-dihydro-5-iodomethyl-4-phenyl-2(3H)-furanone 
• 2678-54-8 ketene diethyl acetal 
• 30828-19-4 ketene diisopropyl acetal 
• 123-76-2 levulinic acid 
• 591-12-8 5-methyl-2-furanone 
• 98-80-6 phenylboronic acid 
• 922-69-0 1,1-dimethoxyethylene 
• 51212-29-4 β-formylbenzenepropanoic acid methyl ester 
• 917-54-4 methyllithium 

Relevant academic research and scientific papers

Europium-Catalyzed Intramolecular Addition of Carboxylic Acid to Nonactivated Alkenes: An Efficient Route to Aryl-Substituted γ-Butyrolactone

Europium(III)triflate has been proved to be an effective catalyst for intramolecular cyclization of aryl-substituted carboxylic acid to afford arylated γ-butyrolactone. Various attractive features, such as broad substrate scope, a wide range of functional

Regioselective β-Arylation of α-Angelica Lactone through Isomerization/Addition under Mild Conditions

The conversion of biomass-based platform molecules into various high-value chemicals greatly promotes the utilization of renewable biomass resources. Herein, an example of Rh-catalyzed β-arylation of levulinic-acid-derived α-angelica lactone was reported, providing the γ-lactone-structure products with high regioselectivity. Both arylboronic and alkenylboronic acids could be applied in this transformation. This reaction tolerated a variety of synthetically important functional groups. Moreover, the obtained γ-lactone products could be readily converted to high-value products such as 1,4-diols and γ-methoxy-carboxylates.

Copper-catalysed intramolecular O-H addition to unactivated alkenes

Intramolecular cyclisation of ω-alkenoic acids and alkenols can be achieved using a catalytic amount of Cu(OTf)2 to afford lactones and cyclic ethers, offering a practical alternative to existing catalysts.

Intramolecular additions of alcohols and carboxylic acids to inert olefins catalyzed by silver(I) triflate

(Chemical Equation Presented) Intramolecular additions of hydroxyl or carboxyl groups to inert olefins catalyzed by simple silver(I) triflate are described. Good to excellent yields can be obtained for a range of substrates under relatively mild conditions. This reaction represents one of the simplest methods to construct cyclic ethers or lactones.

The first synthesis of cyclopropanone acetals from the reaction of Fischer carbene complexes with ketene acetals

The reaction of iso-propoxy stabilized Fischer carbene complexes with ketene acetals gives moderate to excellent yields of cyclopropanone acetals when carried out under a carbon monoxide atmosphere. This is in contrast to the known reaction of methoxy substituted complexes which give cyclic ortho esters under the same conditions. A mechanism is proposed which involves a branch point between the two products as the zwitterionic intermediate resulting from nucleophilic addition of the ketene acetal to the carbene carbon. A 1,3-migration of the methoxyl group to the cationic center leads to the ortho ester and a ring closure by backside attack leads to the cyclopropanone acetal. A double-labeling experiment shows that the 1,3-migration occurs by an intramolecular process that is proposed to involve a bridging oxonium ion. The effect of the isopropoxy group is thus interpreted to be to sterically hinder the formation of a bridged oxonium ion.

Synthesis of chiral organotin reagents: Synthesis of diphenyl-{(1S,2R,3S,4R)-3-(alkoxymethyl)bicyclo[2.2.1]heptan-2-yl}tin hydrides. X-Ray crystal structure of (R)-4,4-dimethyl-2-oxotetrahydrofuran-3-yl (1S,2S,3R,4R)-3-triphenylstannylbicyclo[2.2.1]hept-5-ene-2-carboxylate

Conditions have been developed for the stereoselective Diels-Alder addition of cyclopentadiene to (R)-4,4-dimethyl-2-oxotetrahydrofuran-3-yl (E)-3-triphenylstannylprop-2-enoate 10 to give the endo-adduct 14 whose structure has been confirmed by X-ray crystallography. The adduct 14 is converted into (1S,2R,3S,4R)-3-hydroxymethylbicyclo[2.2.1]heptan-2-yl(triphenyl)stannane 22 which is shown to have an enantiomeric excess (ee) of 94%. This alcohol has been converted into its methyl ether (-)-3, trityl ether 25, tert-butyldimethylsilyl ether 26 and 1-naphthoate 27 which give the tin hydrides 4, 31-34 on treatment with iodine and sodium borohydride. Aspects of the chemistry of these enantiomerically enriched tin hydrides are briefly discussed.

Synthesis of chiral organotin reagents: Diels-Alder reactions of methyl 3-(triphenylstannyl)acrylate: Synthesis of diphenyl-(3-substituted bicyclo[2.2.1]heptan-2-yl)tin hydrides

Cyclopentadiene undergoes Diels-Alder reactions with methyl (E)- and (Z)3-(triphenylstannyl)acrylates 5 and 6 to give the endo-cycloadduct 9, and a mixture of the exo- and endo-isomers 10 and 11, respectively. The endo-product 9 is reduced to the alcohol 12 which is protected as its methyl ether 13. Attempts to remove one of the phenyl substituents from the tin using iodine are complicated by destannylation to the tricyclic iodide 14. However, after hydrogenation, treatment with 1 mol equivalent of iodine gives the tin iodide 17 which is reduced to the tin hydride 18. The hydroxyalkyltin hydride 21 is similarly prepared. The unsaturated tin hydrides 24 and 26 have been prepared by reduction of the Diels-Alder adducts 23 and 25 obtained from cyclopentadiene and methyl (Z)-3-(chlorodiphenylstannyl)acrylate. The tin hydrides 18 and 21 are found to undergo free-radical reactions as exemplified by addition to methyl propiolate and reductive dehalogenation of the iodo lactone 30.

Ester Groups as Effective Ligands in Chelate-Controlled Additions of Cuprates and Grignard Reagents to Chiral β-Formyl Esters

Addition of cuprates to chiral methyl β-formyl carboxylates 1a-1d provided γ-lactones 2-7 in excellent trans-selectivity.The high diastereofacial selectivity was only obtained employing diethyl ether as solvent while tetrahydrofuran gave inferior results.Similar solvent effects were observed in the additions of various Grignard reagents to 1a, which afforded γ-lactones 2, 3, 12, and 13 in moderate trans-selectivity.The best solvent for these reactions was dichloromethane.The 1,3-induction of cuprate additions was studied by using aldehydes 8a-8c.The results obtained were interpreted in terms of chelate-controlled additions with formation of seven-membered ring chelates which involve both carbonyl functions of aldehyde 1 or 8.The function of ester groups as effective ligands of lithium or MgX cations may also be of importance for other stereoselective reactions employing organometallic reagents.