Synthesis of Substituted Hydrindanes. Part I. Products Arising from the Cyclization of Acetonyl Cyclohexanones and Acetonyl Cyclohexadiones
作者:André Beth、Jacques Pelletier、Robert Russo、Marcel Soucy、Robert H. Burnell
DOI:10.1139/v75-209
日期:1975.5.15
The preparation and cyclizations of certain 1,4-diketones have been studied as a route to substituted hydrindan-2-one systems. Other types of products encountered are also described.
Starting from 4-methylcyclohexanone (7), a concise total synthesis of the pinguisane-type sesquiterpenoid acutifolone A, in racemic form, has been accomplished in 14 steps with an overall yield of 14.5%.
Efficient Synthesis of Furan-2-ylacetates, 7-(Alkoxycarbonyl)benzofurans, and 7-(Alkoxycarbonyl)-2,3-dihydrobenzofurans Based on Cyclization Reactions of Free and Masked Dianions: A “Cyclization/Dehydrogenation” Strategy
作者:Esen Bellur、Peter Langer
DOI:10.1021/jo051767i
日期:2005.11.1
A variety of furan-2-ylacetates have been prepared by dehydrogenation of monocyclic 2-alkylidene-tetrahydrofurans, which are readily available by cyclizations of open-chained 1,3-dicarbonyl dianions with 1-bromo-2-chloroethane. 5'H-[2,3']Bifuranyl-2'-ones are available based on sequential "cyclization/dehydrogenation" reactions of alpha-acetyl-gamma-butyrolactones. A variety of 7-(alkoxycarbonyl)-benzofarans and 7-(alkoxycarbonyl)-2,3-dihydrobenzofurans were prepared by a cyclization/ dehydrogenation strategy. These reactions rely on cyclizations of 2-oxocycloalkane-1-carboxylate/derived 1,3-dicarbonyl dianions ("free dianions") or 1,3-bis-silyl enol ethers ("masked dianions") with various 1,2-dielectrophiles.
Anthranilic acid replacements in a niacin receptor agonist
Niacin is an effective drug for raising HDL cholesterol. However, niacin must be taken in large doses and significant side effects are often observed, including facial flushing, loss of glucose tolerance, and liver toxicity. An anthranilic acid was identified as an agonist of the niacin receptor. In order to improve efficacy and provide structural diversity, replacements for the anthranilic acid were investigated and several compounds with improved properties were identified. (C) 2010 Elsevier Ltd. All rights reserved.
On the palladium catalyzed reaction of methallyl-1,1-diacetate with cyclic β-ketoesters. Intervention of hidden mechanisms.
Palladium(0) catalysis in the title reaction causes the release of methacrolein which competes effectively with the pi-allyl species in product formation, a bicycloannulated derivative, when DBU is used as base.