A novel reduction of alcohols and ethers with a HSiEt3catalytic B(C6F5)3 system
摘要:
The primary alcohols 1a-d and ethers 4a-b were effectively reduced into the corresponding hydrocarbons 2 by HSiEt3 in the presence of catalytic amounts of B(C6F5)(3). The secondary alkyl ethers 4g,h underwent cleavage and/or reduction under similar reaction conditions to produce either the silyl ether 3k or the corresponding alcohol 5b upon subsequent deprotection with TBAF. The secondary alcohols (1g,h) and tertiary alcohol 1i, as well as tertiary alkyl ether 4i, did not react with the HSiEt3/(B(C6F5)(3) reducing reagent at all. The following relative reactivity order of substrates was found: primary>>secondary>tertiary. The methyl aryl ethers 4c-e and alkyl aryl ether 4f were smoothly deprotected to give the corresponding silyl ethers 3b,h-j in nearly quantitative isolated yields. (C) 1999 Elsevier Science Ltd. All rights reserved.
Use of pseudopterosins for promoting wound healing
申请人:OsteoArthritis Sciences, Incorporated
公开号:US05597808A1
公开(公告)日:1997-01-28
Methods of promoting wound healing and the growth and proliferation of keratinocytes, fibroblasts and endothelial cells are disclosed. These methods comprise contacting a wound with an effective wound healing amount of a composition comprising a pseudopterosin or pseudopterosin derivative.
Methods for treating mammals to reduce pain and/or reduce inflammation are described based on administering to the mammals synthetic ether derivatives of pseudopterosin having the formula: ##STR1## wherein A is an alkyl, aryl or amide group having from 2 to 20 carbon atoms, R.sub.1, R.sub.2 and R.sub.3 are hydrogen or an acyl residue (--COR) having from 1 to 6 carbon atoms, R.sub.4 is hydrogen or --CH.sub.2 OH and R.sub.5 is a hydrocarbon having from 1 to 10 carbon atoms. Also disclosed are synthetic compositions having the above general formula which are useful in the described method.
Conversion of Alkyl Halides into Alcohols via Formyloxylation Reaction with DMF Catalyzed by Silver Salts
作者:Antonio Abad、Consuelo Agulló、Ana C. Cuñat、Ismael Navarro
DOI:10.1055/s-2005-918453
日期:——
transformation of alkyl halides into alcohols via a two-step process based on the reaction with DMF catalyzed by Ag(I) salts followed by acid or basic hydrolysis of the intermediate formate ester has been evaluated. The results show that a large variety of primary and some secondary alkyl halides can be transformed efficiently into the corresponding alcohols, making this alkyl halide to alcohol interconversion
Ether compounds, which are useful as solvents, cosmetics, detergents, lubricants, emulsifiers and so on, are produced by reacting (a) a hydroxy compound with a carbonyl compound of (b) a carbonyl compound under hydrogen atmosphere in the presence of a catalyst with ease and at a low cost. The reaction is carried out while removing out produced water by using a dehydrating agent during the reaction; by distilling off the water by azeotropic dehydration and the like; or by blowing gases such as hydrogen gas to flow through the reaction system.
Hydrogen bonding Part 44 Thermodynamics of complexation of 3,5-dichlorophenol with ketones and ethers in cyclohexane: the Badger–Bauer relationship
作者:Michael H. Abraham、David V. Prior、Ronald A. Schulz、Jeffrey J. Morris、Peter J. Taylor
DOI:10.1039/a708362i
日期:——
Equilibrium constants for 1:1 hydrogen bond complexation between 3,5-dichlorophenol (DCP) and 17 ketones and 12 ethers in cyclohexane solution have been obtained by an FTIR method that takes into account both dimerization of the acid and formation of 2:1 complexes. Enthalpies of complexation for the same ketones and ethers have been determined by a calorimetric method, leading to values of log K, ÎG°, ÎH° and ÎS° for 1:1 complexation in the 29 systems, as well as log K2 for the 2:1 complexation between 2 mol of acid and 1 mol of base. For the ketone systems there is very little variation in the three thermodynamic parameters with alkyl substitution, but for the ethers there are systematic variations depending on the alkyl substituent or if the ethers are cyclic.Values of the OH stretching frequency in the DCP complexes with the ketones and ethers in cyclohexane have been obtained. The band shapes for the DCPâketone complexes are very asymmetric, possibly due to the presence of stereoisomeric complexes, but the νOH band for DCPâether complexes is symmetric and very suitable for the evaluation of any relationship between νOH and ÎH°. It is found that for the complexation of DCP with the 12 aliphatic ethers in cyclohexane, there is almost no connection between the calorimetrically determined ÎH° values and values of ÎνOH.