15186-48-8Relevant articles and documents
A convenient synthesis of 1-[6-Fluoro-(2S)-3H,4H-dihydro-2H-2-chromenyl]- (1R)-1,2-ethanediol and 1-[6-fluoro-(2R)-3H,4H-dihydro- 2H-2-chromenyl]-(1R)-1, 2-ethanediol
Yu, An-Guang,Wang, Nai-Xing,Xing, Ya-Lan,Zhang, Jun-Ping,Yang, Yun-Xu,Wang, Wu-Wei,Sheng, Rui-Long
, p. 1465 - 1467 (2005)
1-[6-Fluoro-(2S)-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2-ethanediol and 1-[6-fluoro-(2R)-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2-ethanediol, important pharmaceutical intermediates, were synthesized from natural chiral pool D-mannitol. Georg Thieme Verlag Stuttgart.
An Esterase-like Lyase Catalyzes Acetate Elimination in Spirotetronate/Spirotetramate Biosynthesis
Lees, Nicholas R.,Han, Li-Chen,Byrne, Matthew J.,Davies, Jonathan A.,Parnell, Alice E.,Moreland, Pollyanna E. J.,Stach, James E. M.,van der Kamp, Marc W.,Willis, Christine L.,Race, Paul R.
, p. 2305 - 2309 (2019)
Spirotetronate and spirotetramate natural products include a multitude of compounds with potent antimicrobial and antitumor activities. Their biosynthesis incorporates many unusual biocatalytic steps, including regio- and stereo-specific modifications, cyclizations promoted by Diels–Alderases, and acetylation-elimination reactions. Here we focus on the acetate elimination catalyzed by AbyA5, implicated in the formation of the key Diels–Alder substrate to give the spirocyclic system of the antibiotic abyssomicin C. Using synthetic substrate analogues, it is shown that AbyA5 catalyzes stereospecific acetate elimination, establishing the (R)-tetronate acetate as a biosynthetic intermediate. The X-ray crystal structure of AbyA5, the first of an acetate-eliminating enzyme, reveals a deviant acetyl esterase fold. Molecular dynamics simulations and enzyme assays show the use of a His-Ser dyad to catalyze either elimination or hydrolysis, via disparate mechanisms, under substrate control.
Synthesis of (-)-tetrodotoxin: Preparation of an advanced cyclohexenone intermediate
Taber, Douglass F.,Storck, Pierre H.
, p. 7768 - 7771 (2003)
The preparation of an advanced intermediate toward the enantioselective synthesis of tetrodotoxin is outlined. The enantiomerically pure cyclopentene 15 was generated from ketone 14 by alkylidene carbene insertion with retention of absolute configuration. An ozonolysis/aldol sequence first produced the trans cyclohexenone, which upon epimerization gave the more stable cis enone 18.
An efficient synthesis of epoxydiynes and a key fragment of Neocarzinostatin chromophore
Baker,Thominet,Britton,Caddick
, p. 45 - 48 (2007)
(Chemical Equation Presented) A key structural feature of the Neocarzinostatin chromophore is a reactive epoxydiyne. We present here a new method for the preparation of epoxydiynes by the addition of an allenyl zinc bromide to a propargylic ketone.
CHRALITY OF PLECTANIAXANTHIN
Roenneberg, Harald,Borch, Gunner,Buchecker, Richard,Arpin, Noel,Liaaen-Jensen, Synnoeve
, p. 2087 - 2090 (1982)
The chirality of plectaniaxanthin, a carotenoid vic. glycol from Plectania coccinea, colud not be determined by the modified Horeau method.Chiroptical correlation of plectaniaxanthin acetonide and (2'S)-16',17'-dinorplectaniaxanthin acetonide was taken as proof of 2'R chirality for natural plectaniaxanthin and its mono- and diesters.The synthesis of the chiral model carotenoid was effected from D-mannitol via 2,3-isopropylidene-D-glyceraldehyde as key synthon.Key Word Index - Plectania coccinea; Ascomycetes; chirality; characteristic carotenoid; plectaniaxanthin; (2'R)-3',4'-didehydro-1',2'-dihydro-β,ψ-carotene-1',2'-diol.
Synthesis, spectroscopic characterization and biological properties of new natural aldehydes thiosemicarbazones
Tarasconi, Pieralberto,Capacchi, Silvia,Pelosi, Giorgio,Cornia, Mara,Albertini, Roberto,Bonati, Antonio,Dall'Aglio, Pier Paolo,Lunghi, Paolo,Pinelli, Silvana
, p. 157 - 162 (2000)
As part of a research programme aimed at the synthesis of compounds with antiviral, antibacterial and antitumor properties and their spectroscopic characterization, new thiosemicarbazones deriving from natural aldehydes have been investigated. These substances contain in the same molecule both a chain with nucleophilic centres N, S with tubercolostatic activity, and a glycosidic or alkyl moiety (modified glycosides and nucleosides have recently received a great deal of attention in the fields of neoplastic diseases and viral infections). In this paper the synthesis and the characterization of these compounds by means of 1H NMR, IR, and MS techniques is reported. Biological studies have involved both inhibition of cell proliferation and apoptosis tests on human leukemia cell line U937. (C) 2000 Elsevier Science Ltd.
Synthesis of 2,3-O-Isopropylidene-D-glyceraldehyde in High Chemical and Optical Purity: Observations on the Development of a Practical Bulk Process
Schmid, Christopher R.,Bryant, Jerry D.,Dowlatzedah, Mandy,Phillips, Joseph L.,Prather, Douglas E.,et al.
, p. 4056 - 4058 (1991)
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A nitrilase-mediated entry to 4-carboxymethyl-β-lactams from chemically prepared 4-(cyanomethyl)azetidin-2-ones
Decuyper, Lena,Piens, Nicola,Mincke, Jens,Bomon, Jeroen,De Schrijver, Bert,Mollet, Karen,De Winter, Karel,Desmet, Tom,D'Hooghe, Matthias
, p. 54573 - 54579 (2016)
(3R,4S)-3-Alkoxy/aryloxy-4-(cyanomethyl)azetidin-2-ones were efficiently prepared from readily available 1,2:5,6-di-O-isopropylidene-d-mannitol by means of a classical organic synthesis approach via 4-hydroxymethyl-β-lactams as key intermediates. The corresponding 4-carboxymethyl-β-lactams were subsequently obtained after selective hydrolysis of the nitrile functionality by means of a nitrilase enzyme without affecting the sensitive four-membered ring system, hence overcoming the difficulties associated with the chemical hydrolysis approach. Thus, the implementation of a biocatalytic step allows a convenient synthetic route to new 4-carboxymethyl-β-lactams as versatile building blocks for further elaboration.
SYNTHESIS OF A NOVEL PROSTAGLANDIN H2 (PGH2) ANALOGUE
Elder, John S.,Mann, John,Walsh, E. Brian
, p. 3117 - 3126 (1985)
We describe a five-step synthesis of a PGH2 analogue from (R)-glyceraldehyde acetonide via formation of 1,2(S)-O-isopropylidene-hex-3(E)-en-5-one, conjugate addition of prostanoid C13-C20 side-chain as the cuprate with C1-C7 side-chain used to quench the resultant enolate, and finally acid-catalysed ketal exchange to provide the desired analogue.
Synthesis of the AB ring system of clifednamide utilizing Claisen rearrangement and Diels-Alder reaction as key steps
Loke, Inga,Bentzinger, Guillaume,Holz, Julia,Raja, Aruna,Bhasin, Aman,Sasse, Florenz,K?hn, Andreas,Schobert, Rainer,Laschat, Sabine
, p. 884 - 894 (2016)
In order to construct the functionalized AB ring system of clifednamide, member of the class of macrocyclic tetramic acid lactams, a synthesis was developed which utilized an Ireland-Claisen rearrangement and an intramolecular Diels-Alder reaction. Starting from di-O-isopropylidene-d-mannitol the allyl carboxylate precursor for the sigmatropic rearrangement was prepared. This rearrangement proceeded diastereoselectively only in the presence of an allyl silyl ether instead of the parent enone in the side chain, as suggested by deuteration experiments. A subsequent Diels-Alder reaction yielded the target ethyl hexahydro-1H-indene-carboxylate with high diastereoselectivity. Quantum-chemical investigations of this intramolecular Diels-Alder reaction support the proposed configuration of the final product.
Diastereomeric enols and enol derivatives of 8-fluoro-5,11-dihydro-10H- dibenzo[a,d]cyclohepten-10-one with a chiral 11-substituent
Compernolle, Frans,Toppet, Suzanne,Brossette, Thierry,Mao, Hua,Koukni, Mohamed,Kozlecki, Tomasz,Medaer, Bart,Guillaume, Michel,Lang, Yolande,Leurs, Stef,Hoornaert, Georges J.
, p. 1586 - 1592 (2006)
Aldol condensation of 8-fluoro-5,11-dihydro-10H-dibenzo[a,d]cyclohepten-10- one and (4S)-2,2-dimethyl-1,3-dioxolane-4-carbaldehyde provides access to the corresponding (E,Z)-α,β-unsaturated ketones with a (4R)-chiral 11-substituent. Subsequent hydrogenation affords a mixture of (11R)/ (11S)-epimeric ketones, which undergoes base-catalysed equilibration resulting in selective crystallisation of the (11R) epimer. The enol intermediate and acyclic enol derivatives are shown to exist as two slowly interconverting conformers with a high inversion barrier of the 10,11-disubstituted ring. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Clavulanic Acid Biosynthesis: the Stereochemical Course of β-Lactam Formation from Chiral Glycerol
Townsend, Craig A.,Mao, Shi-shan
, p. 86 - 89 (1987)
The overall stereochemical course of β-lactam formation in clavulanic acid was determined to be retention from (1R,2R)- and (1S,2R)-,glycerol.
High-selectivity synthesis method for gemcitabine intermediate
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Paragraph 0051-0052, (2021/01/29)
The invention discloses a high-selectivity synthesis method for a gemcitabine intermediate. The high-selectivity synthesis method specifically comprises the following process: Step 1, synthesis of T1;Step2, synthesis of T2, to be specific, 550kg of hydrogen peroxide is dropwise added into the T1, and a reaction is controlled to produce the T2; Step3, synthesis of T3, to be specific, sodium acetate trihydrate or sodium carbonate is added into a reaction kettle, the PH value is adjusted with glacial acetic acid, a 10%-15% sodium hypochlorite aqueous solution is dropwise added, and a reaction iscontrolled to produce the T3; Step 4, synthesis of T4; Step 5, synthesis of T5; Step 6, synthesis of T6; Step 7, synthesis of T7; Step 8, synthesis of T8; and Step9, T8 configuration transformation.The high-selectivity synthetic method for the gemcitabine intermediate can reduce the production cost, and meanwhile, can also increase the yield of the gemcitabine intermediate.
Preparation method R - (+) -2, 2 - dimethyl -1 and 3 - dioxolane -4 - formaldehyde
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Paragraph 0021-0037, (2021/11/19)
The invention relates to R - (+) -2. 2 - Dimethyl -1, 3 - dioxolane -4 - formaldehyde preparation method belongs to the technical field of drug intermediate synthesis. In order to solve the problems that the existing wastewater is large in pollution and not high in selectivity, the method comprises R - or -2 of catalytic amount of a phase transfer catalyst quaternary ammonium salt and an oxidizing agent, wherein the substrate type 2 - compound diacetone -1 BPCC mannitol catalytic oxidation reaction is converted into a product type - D - II 3 - compound -4 - (-2 I +) PCC in an alkyl halide hydrocarbon solvent R . 2 - Dimethyl -1, 3 - dioxolane -4 - formaldehyde. The method has the effects of high product yield and purity quality, the product yield reaches above 95%, the purity reaches 99.5% or more, a large amount of wastewater is greatly reduced, and the method has the advantage of environmental friendliness.
Total Synthesis of the Putative Structure of Asperipin-2a and Stereochemical Reassignment
Hutton, Craig A.,Shabani, Sadegh,White, Jonathan M.
supporting information, p. 7730 - 7734 (2020/10/09)
The total synthesis of the putative structure of asperipin-2a is described. The synthesis features ether cross-links between the phenolic oxygen of Tyr6 and the β position of Tyr3 and the phenolic oxygen of Tyr3 and the β position of Hpp1 in the unique 17- and 14-membered bicyclic structure of asperipin-2a, respectively. The synthesized putative structure does not match the natural product, and a stereochemical reassignment is postulated.