694-98-4Relevant academic research and scientific papers
Synthesis of 2-substituted ±-(2R,3R,5R)-tetrahydrofuran-3,5-dicarboxylic acid derivatives
Wang,Wang,Chen,Gentles,Sowin
, p. 2052 - 2056 (2001)
An efficient synthesis of 2-substituted (±)-(2R,3R,5R)-tetrahydrofuran-3,5-dicarboxylic acid derivatives has been developed. Starting from 5-norborne-2-ol, the key intermediate (±)-methyl 5,6-exo(isopropylidenedioxy)-2-oxabicyclo[2.2.1]heptane-3-exo-carboxylate (15) was synthesized in an efficient six-step sequence. The key transformation is the base-catalyzed methanolysis-rearrangement of (±)-6,7-exo,exo-(isopropylidenedioxy)-4-exo-iodo-2-oxabicyclo [3.2.1]octan-3-one (14). Further manipulation of the 3-substituent of (±)-methyl 5,6-exo,exo-(isopropylidenedioxy)-2-oxabicyclo[2.2.1] heptane-3-exo-carboxylate (15) followed by deprotection of the diol moiety and ring opening catalyzed by RuCl3/NaIO4 gave the title compounds in good yield.
Total Synthesis of Δ12-Prostaglandin J3: Evolution of Synthetic Strategies to a Streamlined Process
Nicolaou,Pulukuri, Kiran Kumar,Yu, Ruocheng,Rigol, Stephan,Heretsch, Philipp,Grove, Charles I.,Hale, Christopher R. H.,ElMarrouni, Abdelatif
, p. 8559 - 8570 (2016/07/11)
The total synthesis of Δ12-prostaglandin J3(Δ12-PGJ3, 1), a reported leukemia stem cell ablator, through a number of strategies and tactics is described. The signature cross-conjugated dienone structural motif of 1 was forged by an aldol reaction/dehydration sequence from key building blocks enone 13 and aldehyde 14, whose lone stereocenters were generated by an asymmetric Tsuji–Trost reaction and an asymmetric Mukaiyama aldol reaction, respectively. During this program, a substituent-governed regioselectivity pattern for the Rh-catalyzed C?H functionalization of cyclopentenes and related olefins was discovered. The evolution of the synthesis of 1 from the original strategy to the final streamlined process proceeded through improvements in the construction of both fragments 13 and 14, exploration of the chemistry of the hitherto underutilized chiral lactone synthon 57, and a diastereoselective alkylation of a cyclopentenone intermediate. The described chemistry sets the stage for large-scale production of Δ12-PGJ3and designed analogues for further biological and pharmacological studies.
PHARMACEUTICAL COMPOSITIONS AND METHODS FOR RELIEVING PAIN AND TREATING CENTRAL NERVOUS SYSTEM DISORDERS
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Page/Page column 79-80, (2008/06/13)
Patients susceptible to or suffering from disorders, such as central nervous system disorders, which are characterized by an alteration in normal neurotransmitter release, such as dopamine release (e.g., Parkinsonism, Parkinson's Disease, Tourette's Syndrome, attention deficient disorder, or schizophrenia), are treated by administering a compound of Formulas (1 or 2), as described herein. The compounds of Formulas (1 and 2) are also useful for treating pain, and treating drug addiction, nicotine addiction, and/or obesity. The compounds can exist as individual stereoisomers, racemic mixtures, diastereomers and the like.
Five-membered carbocyclic and heterocyclic inhibitors of neuraminidases
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, (2008/06/13)
Disclosed are compounds of the formula: which are useful for inhibiting neuraminidases from disease-causing microorganisms, especially, influenza neuraminidase. Also disclosed are compositions and methods for preventing and treating diseases caused by microorganisms having a neuraminidase, processes for preparing the compounds and synthetic intermediates used in these processes.
Ring-opening metathesis - Cross-metathesis reactions (ROM-CM) of substituted norbornadienes and norbornenes
Mayo, Peter,Tam, William
, p. 9513 - 9525 (2007/10/03)
Ring-opening metathesis - cross-metathesis reactions (ROM-CM) of substituted norbornadienes and norbornenes were investigated. The reactions with symmetrical 2,3-disubstituted norbornadienes were found to be highly chemoselective, with the ROM reactions occurring only on the less substituted or less sterically hindered double bonds regardless of the electronic nature of the substituents, giving highly substituted cyclopentenes in moderate to good yields. This study provides an efficient method for the stereoselective synthesis of highly substituted cyclopentenoids. Long-range electronic effect of a remote substituent on unsymmetrical norbornenes in the ROM-CM reactions was also investigated. Low levels of regioselectivities were observed (50:50 to 69:31) with various remote substituents on the norbornenes.
Synthesis of norborn-5-en-2-one and its homologue
Minuti,Taticchi,Marrocchi,Costantini,Wenkert
, p. 707 - 710 (2007/10/03)
Diels-Alder reaction of cyclopentadiene and 1,3-cyclohexadiene with propiolic ester 6 under thermal and high pressure conditions gave an epimer mixture of ketoester 8 and 10, subsequently converted into bicyclic ketones 1 and 2.
Remote substituent effects on the oxymercuration of 2-substituted norbornenes: An experimental and theoretical study
Mayo,Orlova,Goddard,Tam
, p. 5182 - 5191 (2007/10/03)
The effect of a remote substituent on regioselectivity in the oxymercuration of 2-substituted norbornenes has been investigated experimentally and theoretically using density functional theory (DFT). Regioselectivities of 1:1 to 14:1 were observed with various 2-substituted norbornenes. Exo-2-substituted norbornenes always gave greater regioselectivities compared to the corresponding endo-2-substituted norbornenes. The effects of solvents on the regioselectivity have also been examined, and ethereal solvents were found to be the best choice giving the optimal yield and regioselectivity. The relative rate of oxymercuration was estimated by competition experiments. The least reactive substrate (X = OAc) gave the highest regioselectivity. According to DFT predictions, the increased difference between the reaction barriers that results in the greater regioselectivity is correlated directly with the larger polarity of the C=C double bond, which is attacked by the mercury and oxygen. A number of stable exo and endo conformers were predicted. All exo conformers show the same polarity of the double bond, while some endo conformers have a reversal of this polarity. All the conformers except those with the OAc substituent are very close in energy and thus should react. The existence of a mixture of endo conformers with the C=C double bond of opposite polarity clearly explains a decrease in regioselectivity for the endo species. The origin of the greatest regioselectivity for the OAc-2-norbornenes lies in the fact that the conformer with the largest polarity is notably lower in energy than others due to an internal C-H-O hydrogen bond.
New synthesis of 2-aminobicyclo[2.1.1]hexane-2,5-dicarboxylic acid-I (ABHxD-I), a potent metabotropic receptor agonist
Conti, Paola,Kozikowski, Alan P.
, p. 4053 - 4056 (2007/10/03)
A new versatile synthesis of racemic ABHxD-I, a potent mGluR agonist, is presented. The synthesis was achieved by means of a Wolff rearrangement, which converted a 3-diazobicyclo[2.2.1]heptan-2-one into a bicyclo[2.1.1]hexane derivative. (C) 2000 Elsevier Science Ltd.
Oxygen transfer reactions from an oxaziridinium tetrafluoroborate salt to olefins
Lusinchi, Xavier,Hanquet, Gilles
, p. 13727 - 13738 (2007/10/03)
Oxaziridinium 5 efficiently epoxidises olefins. It reacts as an electrophilic reagent and does not transfer its oxygen to deactivated double-bonds or carbonyl functions. Epoxidation of cyclic allylic acetates shows a remarkable diastereoselectivity leading to the syn isomer. We propose that the epoxidation reaction proceeds through a one-step process.
A versatile cobalt(II)-Schiff base catalyzed oxidation of organic substrates with dioxygen: Scope and mechanism
Punniyamurthy,Bhatia, Beena,Reddy, M. Madhava,Maikap, Golak C.,Iqbal, Javed
, p. 7649 - 7670 (2007/10/03)
Cobalt(II) complex 1a-f derived from Schiff bases act as efficient catalysts during the oxidation of wide range of organic substrates(e.g. alkenes, alcohols, benzylic compounds and aliphatic hydrocarbons) with dioxygen in the presence of aliphatic aldehydes or ketones or ketoesters. EPR studies on 1a-f complexes suggest that the aliphatic carbonyl compounds promote the formation of a cobalt(II)-superoxo species responsible for the oxidation of organic compounds. These studies also demonstrate the role of ligands on cobalt in controlling the chemoselectivity of these oxidations. A plausible mechanistic rational is also provided for these oxidations.
