21573-31-9Relevant academic research and scientific papers
Modular Total Synthesis of iso-Archazolids and Archazologs
Dedenbach, Simon,Menche, Dirk,Rivière, Solenne,Ruiz, Johal,Scheeff, Stephan
, p. 10190 - 10223 (2021/08/16)
Full details on the design, development, and successful implementation of suitable synthetic strategies directed toward the total synthesis of iso-archazolids and archazologs are reported. Both a biomimetic and a multistep total synthesis of iso-archazolid B, the most potent and least abundant archazolid, are described. The bioinspired conversion from archazolid B was realized by a high-yielding 1,8-Diazabicyclo[5.4.0]undec-7-ene catalyzed one-step double-bond shift. A highly stereoselective total synthesis was accomplished in 25 steps, involving a sequence of highly stereoselective aldol reactions, an efficient aldol condensation to forge two elaborate fragments, and a challenging ring-closing metathesis macrocyclization with an unusual Stewart-Grubbs catalyst. These strategies proved to be generally useful and could be successfully implemented for the preparation of three novel iso-archazolids as well as five novel archazologs, lacking the thiazole side chain. A wide variety of further archazolids and archazologs may now be targeted for exploration of the promising anticancer potential of these polyketide macrolides.
Fluorinated Musk Fragrances: The CF2Group as a Conformational Bias Influencing the Odour of Civetone and (R)-Muscone
Callejo, Ricardo,Corr, Michael J.,Yang, Mingyan,Wang, Mingan,Cordes, David B.,Slawin, Alexandra M. Z.,O'Hagan, David
, p. 8137 - 8151 (2016/06/13)
The difluoromethylene (CF2) group has a strong tendency to adopt corner over edge locations in aliphatic macrocycles. In this study, the CF2group has been introduced into musk relevant macrocyclic ketones. Nine civetone and five muscone analogues have been prepared by synthesis for structure and odour comparisons. X-ray studies indeed show that the CF2groups influence ring structure and they give some insight into the preferred ring conformations, triggering a musk odour as determined in a professional perfumery environment. The historical conformational model of Bersuker and co-workers for musk fragrance generally holds, and structures that become distorted from this consensus, by the particular placement of the CF2groups, lose their musk fragrance and become less pleasant.
METHOD FOR PRODUCING 7-OCTENAL
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Paragraph 0130; 0131; 0132; 0172; 0173; 0174; 0175, (2015/07/22)
Provided is a method for highly selectively producing 7-octenal with a high conversion ratio through the isomerization reaction of 2,7-octadiene-1-ol. Specifically, provided is a method for producing 7-octenal, in which a copper-based catalyst is obtained by reducing a copper-based catalyst precursor described below, and an isomerization reaction of 2,7-octadiene-1-ol is caused in a gas phase using a fixed-bed reaction in the presence of the obtained copper-based catalyst. The copper-based catalyst precursor: a copper-based catalyst precursor obtained by calcining a mixture containing copper, iron, aluminum, and calcium silicate in which an atomic ratio of iron and aluminum to copper [(Fe+Al)/Cu] is in a range of 1.71 to 2.5, an atomic ratio of aluminum to iron [Al/Fe] is in a range of 0.001 to 3.3, and calcium silicate is contained in a range of 15% by mass to 65% by mass at a temperature in a range of 500°C to 1,000°C.
The difluoromethylene (CF2) group in aliphatic chains: Synthesis and conformational preference of palmitic acids and nonadecane containing CF2 groups
Wang, Yi,Callejo, Ricardo,Slawin, Alexandra M.Z.,O'Hagan, David
supporting information, p. 18 - 25 (2014/01/23)
The syntheses of palmitic acids and a nonadecane are reported with CF 2 groups located 1,3 or 1,4 to each other along the aliphatic chain. Specifically 8,8,10,10- and 8,8,11,11-tetrafluorohexadecanoic acids (6b and 6c) are prepared as well as the singly modified analogue 8,8-difluorohexadecanoic acid (6a). Also 8,8,11,11-tetrafluorononadecane (27) is prepared as a pure hydrocarbon containing a 1,4-di-CF2 motif. The modified palmitic acids are characterized by differential scanning calorimetry (DSC) to determine melting points and phase behaviour relative to palmitic acid (62.5 °C). It emerges that 6c, with the CF2 groups placed 1,4- to each other, has a significantly higher melting point (89.9 °C) when compared to the other analogues and palmitic acid itself. It is a crystalline compound and the structure reveals an extended anti-zig-zag chain. Similarly 8,8,11,11- tetrafluorononadecane (27) adopts an extended anti-zig-zag structure. This is rationalized by dipolar relaxation between the two CF2 groups placed 1,4 to each other in the extended anti-zig-zag chain and suggests a design modification for long chain aliphatics which can introduce conformational stability.
A relay ring-opening/double ring-closing metathesis strategy for the bicyclic macrolide-butenolide core structures
Halle, Mahesh B.,Fernandes, Rodney A.
, p. 63342 - 63348 (2015/02/19)
A concise strategy has been developed for the synthesis of the bicyclic macrolide-butenolide core structures of various natural products with the macrolide ring size ranging from 12- to 16-membered. The bicyclic structure was easily assembled using the relay ring-opening/double ring-closing metathesis strategy. An efficient synthesis of (±)-desmethyl manshurolide has been achieved as an application of this strategy. This journal is
A tandem 1,3-H-shift-6π-electrocyclization-cyclic 2-amido-diene intramolecular Diels-Alder cycloaddition approach to BCD-ring of atropurpuran
Hayashi, Ryuji,Ma, Zhi-Xiong,Hsung, Richard P.
supporting information; scheme or table, p. 252 - 255 (2012/03/08)
An approach toward the BCD-ring of atropurpuran via a sequence of allenic 1,3-H shift, 6π-electron pericyclic ring closure, and intramolecular Diels-Alder cycloaddition of cyclic 2-amidodiene is described.
METHOD FOR PRODUCING HIGH PURITY TERMINAL OLEFIN COMPOUND
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Page/Page column 4, (2012/02/06)
An industrially advantageous method for producing a high purity terminal olefin is disclosed, comprising the steps of (a) contacting a mixture comprising a terminal olefin represented by formula (1): and one or more corresponding internal olefins as impurities, with a brominating agent in the presence of water or an alcohol, to convert the internal olefin(s) to compound(s) having a higher boiling point than the terminal olefin; and (b) purifying the terminal olefin by distillation from the reaction mixture.
METHOD FOR PRODUCING CARBONYL COMPOUND AN PRO-OXIDANT USED FOR PRODUCTION OF CARBONYL COMPOUND
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Page/Page column 12; 14-15, (2009/08/16)
The invention provides a process for the preparation of a carbonyl compound in high efficiency by oxidizing an alcohol. The process for the preparation of a carbonyl compound of the present invention includes a step of oxidizing an alcohol in the presence of a compound of the formula (I) or a derivative or a salt thereof, and an oxidant, wherein R1 and R2 independently represent hydrogen, a halogen, a nitro or acidic group, or an alkyl or alkoxy group, each of which optionally has a substituent, or R1 and R2 combine the two carbon atoms to which they are boned to form an aromatic ring.
Combination of RCM and the Pauson-Khand reaction: One-step synthesis of tricyclic structures
Rosillo, Marta,Arnaiz, Eduardo,Abdi, Delbrin,Blanco-Urgoiti, Jaime,Dominguez, Gema,Perez-Castells, Javier
experimental part, p. 3917 - 3927 (2009/04/07)
The combination of ring-closing metathesis (RCM) followed by an intramolecular Pauson-Khand reaction gives direct entry to tricyclic compounds. The RCM was carried out on a hexacarbonylcobalt-complexed alkyne, this complex acting as a protecting group against enyne metathesis. The procedure was studied for dienynes containing heteroatoms and allows the building of [6,5,5] and [7,5,5] tricyclic systems. The feasibility of the process depends strongly on the nature of the substrate. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
