Voies Nouvelles en Synthèse de Prostaglandins (1)

Crabbé, Pierre; Barreiro, Eliezer J.; Choi, Ha-Soon; Cruz, Anais Vieira Da; Deprés, Jean‐Pierre; Gagnaire, G.; Greene, Andrew E.; Meana, M. C.; Padilla, Antonio; Williams, Lindsey W.

doi:10.1002/bscb.19770860117

Cited by 14 publications

(3 citation statements)

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“…Durante os quatro anos de treinamento doutoral que culminaram com a obtenção do título de Docteur-Ès-Sciences d´État, em 23 de junho de 1978, com a defesa da Tese intitulada Synthèse de Nouvelles 11-Deoxy-Prostaglandines: Voie de l'alfa-tropolone, 4 que foi aprovada pela Banca Examinadora composta pelos Professores Pierre Crabbé, na condição de presidente, Charles Jeffort (Université de Géneve, Suíça), Claude Béguin (USMG), Cuong Lu-Duc (USMG) e Francis Rouessac (Université de Le Mans). Durante este doutoramento, que viria a render nove publicações em revistas científicas indexadas, 5,6 forma-se a percepção das condições intelectuais e materiais necessárias e essenciais à realização da atividade de pesquisa científica ética e conduzida pela meritocracia, na área da Química Medicinal, principal vertente do Figura 3. Novos análogos da PGE 1 sintetizados pela via da -tropolona 6,9 Figura 4.…”

Section: Preâmbulounclassified

“…Durante este doutoramento, que viria a render nove publicações em revistas científicas indexadas, 5,6 forma-se a percepção das condições intelectuais e materiais necessárias e essenciais à realização da atividade de pesquisa científica ética e conduzida pela meritocracia, na área da Química Medicinal, principal vertente do Figura 3. Novos análogos da PGE 1 sintetizados pela via da -tropolona 6,9 Figura 4. Reação de organocuprato misto com acetato propargílico, utilizada na síntese de PG´s alênicas 7,8,10,11…”

Section: Preâmbulounclassified

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The Long Legs of the Laboratory for the Evaluation and Synthesis of Bioactive Substances (LASSBio^®; http://www.farmacia.ufrj.br/lassbio): Historic and Perspectives

Barreiro¹

2013

Revista Virtual De Química

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The Long Legs of the Laboratory for the Evaluation and Synthesis of Bioactive Substances (LASSBio^®; http://www.farmacia.ufrj.br/lassbio): Historic and Perspectives

Barreiro¹

2013

Revista Virtual De Química

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“…A number of years ago, our laboratory investigated the synthesis of natural and modified prostaglandins . 11-Nor PGE 2 ( 1 ) was prepared for the first time in the context of this program and used to obtain the corresponding novel ring-expanded γ-butyrolactone, γ-butyrolactam, and cyclopentanone derivatives (Scheme ).…”

Section: Introductionmentioning

confidence: 99%

Diverse Natural Products from Dichlorocyclobutanones: An Evolutionary Tale

et al. 2016

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11-Nor PGE2 was prepared in our laboratory several years ago and used to obtain the corresponding ring-expanded γ-butyrolactam, γ-butyrolactone, and cyclopentanone derivatives. The conversion of a cyclobutanone into a cyclopentanone had relatively little precedent and merited further study. It was soon found that the presence of a single chlorine adjacent to the carbonyl not only greatly accelerated the reaction with ethereal diazomethane, but also substantially enhanced its regioselectivity; not surprisingly, a second chlorine further increased both. The confluence of this finding and the discovery by Krepski and Hassner that the presence of phosphorus oxychloride significantly improved the Zn-mediated dehalogenation procedure for the preparation of α,α-dichlorocyclobutanones from olefins provided the starting point for decades' worth of exciting adventures in natural product synthesis. A wide variety of naturally occurring 5-membered carbocycles (e.g., hirsutanes, cuparenones, bakkanes, guaianolides, azulenes) could thus be prepared by using dichloroketene-olefin cycloaddition, followed by regioselective one-carbon ring expansion with diazomethane. Importantly, it was also found that natural γ-butyrolactones (e.g., β-oxygenated γ-butyrolactones, lactone fatty acids) could be secured through regioselective Baeyer-Villiger oxidation of cycloadducts with m-CPBA and that naturally occurring γ-butyrolactam derivatives (e.g., amino acids, pyrrolidines, pyrrolizidines, indolizidines) could be efficiently obtained by regioselective Beckmann ring expansion of the adducts with O-(mesitylenesulfonyl)hydroxylamine (Tamura's reagent). These 5-membered carbocycles, γ-butyrolactones, and γ-butyrolactam derivatives were generally secured in enantiopure form through the use of either intrinsically chiral olefins or olefins bearing Stericol, a highly effective chiral auxiliary developed specifically for this "three-atom olefin annelation" approach. In addition, considerable useful chemistry has been developed in the context of this synthesis program. This includes new methods for olefin vicinal dicarboxylation, β-methylene-γ-butyrolactonization, γ-butyrolactone and δ-valerolactone α-methylenations, transesterification, angelic ester synthesis, chiral enol and ynol ether preparations, dichloroacetylene synthesis, and trans, trans hydroxy triad introduction. This versatile dichlorocyclobutanone-centered approach to natural product synthesis, together with the attendant new methods that have been developed, forms the basis of this Account, which is presented as an evolutionary tale. It is hoped that the Account will stimulate other research groups to seek to exploit the rich chemistry of dichlorocyclobutanones for possible solutions to problems in organic synthesis.

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The Krapcho Dealkoxycarbonylation Reaction of Esters with α‐Electron‐Withdrawing Substituents

Krapcho

Ciganek

2013

Organic Reactions

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The Krapcho reaction involves esters with α‐electron‐withdrawing substituents such as malonates, β‐keto esters, and α‐cyano esters, which undergo dealkoxycarbonylation on being heated in polar aprotic solvents (such as DMSO, DMF, or HMPT) in the presence of water, or in polar aprotic solvents with water in the presence of added salts (such as NaCN, NaCl, LiCl, LiI, or MgCl 2 ). This procedure avoids the use of strongly aqueous acidic and alkaline conditions and tolerates many functional and protecting groups. The chapter presents the mechanistic aspects of this procedure, which include reaction parameters such as solvents, salts, other additives, and the use of microwave irradiation. The diastereoselectivity of protonation of the enolate intermediate leading to the dealkoxycarbonylated products is discussed. Trapping of the intermediate enolate by electrophiles other than a proton is illustrated. Potential side reactions and same‐pot subsequent reactions of substrates are discussed along with functional‐group compatibility for halogens and nitrogen, oxygen, sulfur, selenium, and carbon functional groups. Several examples of applications of this methodology for the synthesis of natural products along with experimental conditions and procedures are presented. Closely related methods are discussed in the Comparison with Other Methods section. The tables, which consist of 371 pages, are grouped according to substrate structure. Selective entries for other methods (excluding classical aqueous acidic or basic methods) are included in the tabular survey for comparative purposes.

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Voies Nouvelles en Synthèse de Prostaglandins (1)

Cited by 14 publications

References 35 publications

The Long Legs of the Laboratory for the Evaluation and Synthesis of Bioactive Substances (LASSBio^®; http://www.farmacia.ufrj.br/lassbio): Historic and Perspectives

The Long Legs of the Laboratory for the Evaluation and Synthesis of Bioactive Substances (LASSBio^®; http://www.farmacia.ufrj.br/lassbio): Historic and Perspectives

Diverse Natural Products from Dichlorocyclobutanones: An Evolutionary Tale

The Krapcho Dealkoxycarbonylation Reaction of Esters with α‐Electron‐Withdrawing Substituents

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Voies Nouvelles en Synthèse de Prostaglandins (1)

Cited by 14 publications

References 35 publications

The Long Legs of the Laboratory for the Evaluation and Synthesis of Bioactive Substances (LASSBio®; http://www.farmacia.ufrj.br/lassbio): Historic and Perspectives

The Long Legs of the Laboratory for the Evaluation and Synthesis of Bioactive Substances (LASSBio®; http://www.farmacia.ufrj.br/lassbio): Historic and Perspectives

Diverse Natural Products from Dichlorocyclobutanones: An Evolutionary Tale

The Krapcho Dealkoxycarbonylation Reaction of Esters with α‐Electron‐Withdrawing Substituents

Contact Info

Product

Resources

About

The Long Legs of the Laboratory for the Evaluation and Synthesis of Bioactive Substances (LASSBio^®; http://www.farmacia.ufrj.br/lassbio): Historic and Perspectives

The Long Legs of the Laboratory for the Evaluation and Synthesis of Bioactive Substances (LASSBio^®; http://www.farmacia.ufrj.br/lassbio): Historic and Perspectives