121902-57-6Relevant academic research and scientific papers
Bent bonds (τ) and the antiperiplanar hypothesis, and the reactivity at the anomeric center in pyranosides
Parent, Jean-Fran?ois,Deslongchamps, Pierre
, p. 11183 - 11198 (2016)
The stereoselectivity of nucleophilic addition on oxocarbenium ions derived from the bicyclic pyranoside model with or without a C2-OR group can be understood through the use of the bent-bond and the antiperiplanar hypothesis in conjunction with the concept of hyperconjugation as an alternative interpretive model of structure and reactivity.
ENZYMATIC RESOLUTION OF RACEMIC BICYCLIC LACTONES BY HORSE LIVER ESTREASE
Guibe-Jampel, E.,Rousseau, G.,Blanco, L.
, p. 67 - 68 (1989)
Optically active lactones were prepared by Horse Liver esterase catalyzed hydrolysis of bicyclic γ-butyrolactones.
OXIDATIVE BISDECARBOXYLATION OF α-ALKOXYMALONIC ACIDS WITH CERIUM(IV)
Salomon, Robert G.,Roy, Subhas,Salomon, Mary F.
, p. 769 - 772 (1988)
Ceric ammonium nitrate is an excellent reagent for preparing carboxylic esters from α-alkoxymalonic acids by oxidative bisdecarboxylation.
Conversion of 5-oxoalkanals to δ-lactones by an intramolecular Tishchenko reaction
Lange, Gordon L.,Organ, Michael G.
, p. 665 - 667 (1991)
Diisobutylaluminum hydride reduction of photoadducts 3 (7,8-tri- and tetrasubstituted l,3,3-trimethyl-2,4-dioxabicyclo-[4.2.0]octan-5-ones), derived from 2,2,6-trimethyl-4/f-l,3-dioxin-4-one (1), gave 6-lactones 7 in good to excellent yields if the workup involved a methanol quench followed by removal of the solvent. We propose that the reaction proceeds by an intramolecular Tishchenko reaction of the intermediate 5-oxoalkanal 5 and is catalyzed by the Lewis acid diisobutylaluminum methoxide, 8. A deuterium labelling experiment supports the mechanistic proposal and the conversion of 5-oxoalkanals other than S illustrates the scope of the procedure. To our knowledge, this is the first report of a true intramolecular Tishchenko reaction.
Photo-induced radical borylation of hemiacetals via C–C bond cleavage
Liu, Qianyi,Zhang, Jianning,Zhang, Lei,Mo, Fanyang
supporting information, (2021/01/05)
In this study, we reported a photo-induced radical borylation of hemiacetal derivatives via C–C bond cleavage. This transformation can be realized under mild conditions with simple reaction settings and irradiation of visible light. A series of substrates, including both cyclic and linear hemiacetal derivatives, were effectively transformed to the borylation product in moderate to good yields. Finally, the mechanism was studied in detail by DFT calculations, suggesting insight of the radical borylation process.
Ruthenium-Promoted Acceptorless and Oxidant-Free Lactone Synthesis in Aqueous Medium
Bhatia, Anita,Kannan, Muthukumar,Muthaiah, Senthilkumar
supporting information, p. 721 - 725 (2019/03/26)
Ruthenium-catalyzed formation of lactones from diols in aqueous medium has been demonstrated. 1,3,5-Triazaphosphaadamantane (PTA) included water-soluble ruthenium complexes [RuCl 2 (PPh 3)(2,6-Py-(CH 2 -PTA) 2 ]·2Br and [RuCl 2 (PPh 3) 2 (2-PyCH 2 PTA)]·Br in the presence of KOH were found to be efficient for the synthesis of lactones from diols. The reported synthetic protocol is green as it uses water as solvent, avoids the use of any hydrogen acceptor/oxidant, and produces hydrogen as the only side product. Mechanistic studies revealed that lactone formation involved aldehyde intermediate and followed dehydrogenative pathway.
Two Types of Cross-Coupling Reactions between Electron-Rich and Electron-Deficient Alkenes Assisted by Nucleophilic Addition Using an Organic Photoredox Catalyst
Tanaka, Yosuke,Kubosaki, Suzuka,Osaka, Kazuyuki,Yamawaki, Mugen,Morita, Toshio,Yoshimi, Yasuharu
, p. 13625 - 13635 (2018/09/25)
Two types of photoreactions between electronically differentiated donor and acceptor alkenes assisted by nucleophilic addition using an organic photoredox catalyst efficiently afforded 1:1 or 2:1 cross-coupling adducts. A variety of alkenes and alcohols were employed in the photoreaction. Control of the reaction pathway (i.e., the formation of the 1:1 or 2:1 adduct) was achieved by varying the concentration of the alcohol used. Detailed mechanistic studies suggested that the organic photoredox catalyst acts as an effective electron mediator to promote the formation of the cross-coupling adducts.
Hydrogenation of coumarin to octahydrocoumarin over a Ru/C catalyst
Bílková, Dana,Jansa, Petr,Paterová, Iva,?erveny, Libor
, p. 957 - 960 (2015/07/01)
The production of octahydrocoumarin, which can serve as a replacement for toxic coumarin, was investigated using 5% Ru on active carbon (Ru/C) as the catalyst for the hydrogenation of coumarin. The hydrogenation was studied by optimizing the reaction conditions (pressure, solvent and coumarin concentration). The activity and selectivity of the Ru/C catalyst were compared for different solvents. The mechanism of coumarin hydrogenation was deduced. The formation of side products was explained. The optimal hydrogenation reaction conditions were: 130 °C, 10 MPa, 60 wt% coumarin in methanol, and 0.5 wt% (based on coumarin) of Ru/C catalyst. At the complete conversion of coumarin, the selectivity to the desired product was 90%.
Stereocontrolled synthesis of substituted bicyclic ethers through oxy-Favorskii rearrangement: Total synthesis of (±)-communiol e
Kobayashi, Shoji,Kinoshita, Tatsuhiro,Kawamoto, Takuji,Wada, Masato,Kuroda, Hiroyuki,Masuyama, Araki,Ryu, Ilhyong
, p. 7096 - 7103 (2011/10/31)
The potential of the oxy-Favorskii rearrangement to form branched cis-fused bicyclic ethers was explored. Both tertiary and quaternary centers were constructed in highly stereospecific manners. Methanol and primary amines were effective nucleophiles for the rearrangement. The total synthesis of (±)-communiol E was achieved based on this method.
NHC-catalyzed ring expansion of oxacycloalkane-2-carboxaldehydes: A versatile synthesis of lactones
Wang, Li,Thai, Karen,Gravel, Michel
supporting information; experimental part, p. 891 - 893 (2009/08/15)
Imidazolinium-derived carbenes catalyze the ring-expansion lactonization of oxacycloalkane-2-carboxaldehydes. A variety of functionalized five-, six-, and seven-membered lactones can be formed efficiently under mild reaction conditions. The success of this new method for the construction of lactones is highly influenced by the electronic nature of the carbene catalyst.
