摘要:

AbstractTransmercurationinvolving the equilibrium process Ph‐HgOAc + ArH ⇆ ArHgOAc(o,m,p)+ PhH, was previously reported to lead to unusual isomer patterns characterized by high proportions ofortho‐isomers irrespective of the nature of the substituent present in ArH1.1,2‐Disubstitutedcompounds ArH were found to produce equilibrium compositions often disagreeing from those calculated on an additive basis, using the data for mono‐substituted mercurials.Naphthylmercuricacetates appeared to constitute the first example of an equilibrium between α‐ and β‐isomers in which the α‐isomer predominates.Interpretations are based on 1) the small steric requirements of the Hg atom, 2) its positive charge, 3) the dipolar nature of the ‐HgOAc group, 4) buttressing effects, 5) mesomeric coupling between a Hg atom

ISSN:0165-0513    

DOI:10.1002/recl.19720910702

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractWe have studied the reactions of alkylperoxy radicals with olefins in an inert solvent and atmosphere. The peroxy radicals react by addition to the double bond, mainly leading to epoxide formation, and by abstraction of allylic hydrogen, followed by termination between allyl and peroxy radicals. Relative and absolute rate constants at 120°C have been determined of the reactions oftert‐butylperoxy radicals with 2,3‐dimethyl‐2‐butene, 1‐hexene, α‐methylstyrene, propene, 3,3‐dimethyl‐1‐butene and styrene, and of α‐cumylperoxy radicals with 3,3‐dimethyl‐1‐butene.We have found that for olefins having allylic hydrogen the abstraction/addition ratio determines the efficiency as well as the rate of epoxide formation, whereas substantial epoxide formation from olefins lacking easily abstractable hydrogen atoms can be expected only if the double bond is sufficiently reactive to suppress the reactions

ISSN:0165-0513    

DOI:10.1002/recl.19720910703

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractPolifungin is a new tetraene antibiotic complex with antifungal activity. It has been shown that four biologically active components are present in this complex, polifunginBbeing the main component differentiating polifungin from nystatin.

ISSN:0165-0513    

DOI:10.1002/recl.19720910704

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

Abstract2H‐Thiopyran and a number of derivatives have been obtained in fair to good yields by heating compounds containing the system C ≡ CCSCC, in hexamethylphosphorictriamide. Mixtures of 2H‐thiopyrans and thiophenes are formed when heating is performed in this solvent or in dimethyl sulfoxide in the presence of amines. Thiopyrans, having an alkyl group on ring carbon atom 4, are partly converted into the “exo”‐compounds 4‐alkylidene‐2,

ISSN:0165-0513    

DOI:10.1002/recl.19720910705

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractEnamines derived from β‐tetralone and morpholine and dimethylamine (Ia,b), react with carbenes IIa,b to give 1:1 adducts IIIa,b and ring‐insertion products IVa,b, respectively. The reaction of pyrrolidine enamine Ic with the carbenes leads to the formation of new types of products which have been identified as VI and VII. Possible mechanisms for the formation of the reaction products are prese

ISSN:0165-0513    

DOI:10.1002/recl.19720910706

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractFrom the ESR and UV spectra the complex TiCl3(CH3CN)3is shown, by means of the crystal‐field theory, to have the configuration with C2vsymmetry rather than that with C3vsymmetry. The ESR and UV spectra of the ion [TiCl2(CH3CN)4]+, formed by adding a chlorine ion acceptor (e.g.TiCl4, SnCl4, AlCl3, FeCl3) to a solution of anhydrous TiCl3in acetonitrile, could be calculated from the crystal‐field parameters, which were determined from the spectra of TiCl3(CH3C

ISSN:0165-0513    

DOI:10.1002/recl.19720910707

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractIn a consecutive series of stereospecific reactions under alternately thermal and photochemical conditionscis‐1,2,3,4,5,6‐hexamethylcyclohexa‐1,3‐dieneI, 3,4,5,6‐tetramethyl‐(Z,Z,E)‐octa‐2,4,6‐trieneII,transf‐1,2,3,4,5,6‐hexamethylcyclohexa‐1,3‐dieneIIIand 3,4,5,6‐tetramethyl‐(Z,Z,Z)‐octa‐2,4,6‐trieneIVhave been synthesized from 1,2,3,4,5‐endo,6‐endo‐hexamethylbicyclo[2.2.0] hex‐2‐ene as the starting material. Thermal ring closure of the trieneIVdid not give thecis‐dieneI, but, among other products, thetrans‐dieneIII. An intermediate product in this reaction is 3,4,5,6‐tetramethyl‐(Z,Z)‐octa‐1,3,5‐trieneV, formed via a [1,7a] H shift.The structure of compoundIVhas been assigned on the basis of chemical and spectroscopic (13C and 220 MHz1H NMR) data.Cis‐dieneIcan, at room temperature, be converted dire

ISSN:0165-0513    

DOI:10.1002/recl.19720910708

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe ½ortho/pararatios for the nitration of twelve alkylbenzenes with nitric acid and acetic anhydride in nitromethane equal those for the nitration with nitric acid and sulfuric acid in nitromethane. This proves also that under the first‐mentioned conditions the nitronium ion is the effective nitrating agent involved in the product‐determining transition st

ISSN:0165-0513    

DOI:10.1002/recl.19720910709

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19720910710

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe isomeric aminobromoquinolines in which amino groups and bromine atoms are attached to the pyridine nucleus were reacted with potassium amide in liquid ammonia at −33°.2‐Amino‐3‐bromo‐ and 2‐amino‐4‐bromo‐quinoline are convertedvia3,4‐didehydroquinoline into 2,3‐diaminoquinoline together with some 2,4‐diaminoquinoline. Ring transformations occur during reactions of 4‐amino‐2‐bromo‐ and 3‐amino‐2‐bromo‐quinoline yielding 4‐amino‐2‐methylquinazoline and 3‐cyanoindole, respectively. 3‐Amino‐4‐bromoquinoline yields ameta‐rearranged substitution producti.e.2,3‐diaminoquinoline, while 4‐amino‐3‐bromoquinoline does not react under the condit

ISSN:0165-0513    

DOI:10.1002/recl.19720910711

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY