- A New Method of Synthesizing 7-(2-Hydroxy-5-oxo-1-cyclopentenyl)heptanoic Acid and Related Compounds
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A useful prostanoid synthon, 7-(2-hydroxy-5-oxo-1-cyclopentenyl)heptanoic acid (3), was prepared from commercially available cyclooctanone in two steps.Nine other related cyclopentanoids which are also valuable synthons for prostaglandins were obtained from 3 in reasonable yields via several steps.The procedure is capable of generating these synthons on a laboratory scale.
- Naora, Hirokazu,Ohnuki, Takashi,Nakamura, Asao
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- A Short Synthesis of 15-Dehydroprostaglandin B1 Methyl Ester
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A new synthetic method for 15-dehydroprostaglandin B1 methyl ester (15-dehydroPGB1 methyl ester) in four steps from commercially available starting materials is described.
- Naora, Hirokazu,Ohnuki, Takashi,Nakamura, Asao
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- Reductive Coupling between C-N and C-O Electrophiles
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The cross-electrophile reaction is a promising strategy for C-C bond formation. Recent studies have focused mainly on reactions with organic halides. Here we report a coupling reaction between C-N and C-O electrophiles that demonstrates the possibility of constructing a C-C bond via C-N and C-O cleavage. Several reactions between benzyl/aryl ammonium salts and vinyl/aryl C-O electrophiles have been studied. Preliminary mechanistic studies revealed that the benzyl ammoniums were activated through a radical mechanism.
- He, Rong-De,Li, Chun-Ling,Pan, Qiu-Quan,Guo, Peng,Liu, Xue-Yuan,Shu, Xing-Zhong
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supporting information
p. 12481 - 12486
(2019/09/04)
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- Unique michael addition-initiated domino reaction for the stereoselective synthesis of functionalized macrolactones from α-nitroketones in water
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(Chemical Equation Presented) A unique domino reaction of α-nitrocycloalkanones with α-alkyl α,β-unsaturated aldehydes in aqueous base was discovered, leading to the one-pot synthesis of hitherto unknown functionalized, bridged, bicyclic lactones containing 10-, 11-, 13-, and 15-membered rings. The structures of these heterocyclic compounds, containing also an unusual 6-hydroxy-1,2-oxazine ring, were determined by spectral and single-crystal X-ray diffraction studies.
- Giorgi, Giorgio,Miranda, Sonia,Lopez-Alvarado, Pilar,Avendano, Carmen,Rodriguez, Jean,Menendez, J. Carlos
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p. 2197 - 2200
(2007/10/03)
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- Practical and User-Friendly Procedure for Michael Reactions of α-Nitroketones in Water
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A variety of α,β-unsaturated carbonyl derivatives gave selective Michael additions with several α-nitrocycloalkanones in water, at room temperature without any added catalyst, or in very dilute, aqueous solutions of potassium carbonate. Both preparative methods constitute new, environmentally benign and more efficient alternatives to previous procedures.
- Miranda, Sonia,López-Alvarado, Pilar,Giorgi, Giorgio,Rodriguez, Jean,Avenda?o, Carmen,Menéndez, J. Carlos
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p. 2159 - 2162
(2007/10/03)
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- Production of cyclopentenylheptanoic acid derivatives
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Cyclopentenylheptanoic acid derivatives having the formula: STR1 wherein R is hydrogen or C1 to C4 alkyl and --(A)-- is: STR2 wherein M is hydrogen or triorganosilyl group, are prepared by reacting a compound having the formula: STR3 ps wherein X is halogen, with a compound having the formula: The derivatives belong to the pharmacologically-active class of compounds called "prostaglandins".
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- Method for manufacture of 7-(2,5-dioxocyclopentyl)heptanoic acid derivative
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A method for the manufacture of a heptanoic acid derivative represented by the formula STR1 wherein R3 stands for an acyloxy group, a halogen atom, or a hydrogen atom, which comprises reacting a cyclooctene derivative represented by the formula STR2 wherein Y stands for --R1, --COR1 or --SiR23, wherein R1 is an alkyl group, an aryl group, or an aralkyl group and R2 is an alkyl group of 1 to 5 carbon atoms, with a compound represented by the formula STR3 wherein R3 has the same meaning as indicated above and X1 and X2 each is a halogen atom, is described along with uses for such compounds.
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- Formation of Glycol Monoacetates in the Oxidation of Olefins Catalyzed by Metal Nitro Complexes: Mono- vs. Bimetallic System
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The oxidation of terminal olefins by bis(acetonitrile)chloronitropalladium(II) (1) in acetic acid leads to a mixture of glycol monoacetate isomers as the main products.Various amounts of ketones and unsaturated acetates are also formed.The rate of formation and the yield of glycol monoacetate decrease with increasing chain length.Cyclic olefins yield no glycol monoacetates.Replacement of acetic acid by stronger or sterically hindered carboxylic acids completely eliminates the formation of glycol monocarboxylates.Introduction of oxygen converts this stoichiometric reaction into a catalytic system.Our studies, including those carried out with complex 1 labeled with 18O in the nitro ligand, suggest that the glycol monoacetates and most of the ketones are the product of oxygen atom transfer from the nitro group, while the unsaturated acetates are the result of a Wacker-type reaction.In the glycol monoacetate, the 18O label is found exclusively in the acetate group.A mechanism which is in agreement with the above observations as well as a comparison of the above reaction with the oxidation of olefins by nitrate ions in the presence of palladium(II) salts is offered.The formation of glycol monoacetates in the monometallic system represented by complex 1 is to be compared with the results obtained in the bimetallic systems consisting of a combination of py(TPP)CoNO2 and either (CH3CN)2PdCl2 or Pd(OAc)2.In the latter systems, ketones or vinyl acetates are found as the predominant products.This fact underlines the difference between the mono- and bimetallic systems and strongly argues against alternative mechanisms involving nitro group transfer from cobalt to palladium before the olefin oxidation takes place.Additional evidence underlining the difference between these two systems is presented.
- Mares, Frank,Diamond, Steven E.,Regina, Francis J.,Solar, Jeffrey P.
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p. 3545 - 3552
(2007/10/02)
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