摘要:

AbstractBicyclic γ‐lactones were found among the products of reaction of two 2‐substituted cyclopentanones with bromoacetic esters and zinc (Reformatsky). The intermediate β‐hydroxy‐acid obtained from 2‐pentylcyclopentanone with zinc andtert‐butyl bromoacetate in benzene was converted to 4‐pentyl‐3,4‐trimethylene‐4‐butanolide in 67% yield. The preparation of 1‐(2‐carboxyethyl)‐2‐(7‐carbox

ISSN:0165-0513    

DOI:10.1002/recl.19730920802

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe racemization‐free synthesis ofN‐phthaloyl amino acids (Pht‐amino acids) from amino acid esters, by usingo‐methoxycarbonylbenzoyl chloride in anhydrous media, is described. TheN‐phthaloyl amino acids and esters from proteins were obtained in high yields.ThreeN‐phthaloyl amino acids were synthesized for the first time:N‐Pht‐LTrp,N‐Pht‐S‐Bzl‐LCys andN‐Pht‐Nim‐Bzl‐LHis.In the case of some sterically hindered amino acids,LIle and α‐amino‐isobutyric acid, the intermediateN‐(o‐methoxycarbonyl

ISSN:0165-0513    

DOI:10.1002/recl.19730920803

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe reactions of dihydroxotetraamminecobalt(III) perchlorate have been studied in an aqueous solution of 8M‐ammonia containing 1.80M‐ammonium perchlorate, at 25°. Under these conditions the isomerization and the uptake of ammonia occur at comparable rates. From the analysis of the absorbance as a function of time it followed thatcisandtransions react with ammonia at nearly equal rates. On the basis of this information the steric factor in the labilization of Co(III) ligand bonds by a coordinated hydroxo group is discu

ISSN:0165-0513    

DOI:10.1002/recl.19730920804

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe preparation of a number of mono‐brominated derivatives ofmeta‐di‐tert‐butylbenzene andtert‐butylbenzene from 3,5‐di‐tert‐butylacetanili

ISSN:0165-0513    

DOI:10.1002/recl.19730920805

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractPhotoaddition of aromatic ketones to 1‐alkyl‐2‐phenylacetylenes RCCC6H5(R = CH3, C2H5) generally affords,viaan oxete derivative, α,β‐unsaturated ketones Ar2CC(C6H5)COR in good or moderate yield.With monosubstituted arylacetylenes Ar′CCH α,β‐unsaturated aldehydes Ar2CC(Ar′)CHO are formed.In the reactions with 9‐xanthenone partial dehydro

ISSN:0165-0513    

DOI:10.1002/recl.19730920806

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractA number of complexes are reported of some metal(II) nitrates and sulfates containing ethylene glycol as the ligand. The general formula is M(EG)xAn, where M = Mn, Co, Ni, Cu, Zn, Mg, Ca and Cd; A = NO −3and SO =4; x = 1 ‐ 4; n = 1 ‐ 2.The compounds were characterized by means of physical measurements and chemical analyses.Ligand field parameters were calculated for the Co, Ni and Cu compounds, and the ligand is placed in the spectrochemical series.The infrared spectra indicate coordination of NO −3and SO =4. A considerable amount of hydrogen‐bonding is present in the complexes.In most of the compounds, the coordination of ethylene glycol is pro

ISSN:0165-0513    

DOI:10.1002/recl.19730920807

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractA general method has been developed for the synthesis of two novel classes of heterocyclic compounds, 2,3‐(or 2,7)‐dihydrothiepins and 2,3‐dihydro‐8H‐thiocins. It comprises the cycloaddition of enamine derivatives of tetrahydro‐thiophen‐3‐ones or 4‐thiacyclohexanone to activated acetylenes, e.g. dimethyl acetylenedicarboxylate, yielding bicyclic adducts, which upon thermal ring opening of the cyclobutene moiety afford the thiepin and thiocin derivatives.The enamine group in these cyclic dienamines can be hydrolysed to give stabilized enols and/or their tautomeric ketones.Peracid oxidation of the sulfur atom in the dihydrothiepins or dihydro‐2H‐thiocins produces the corresponding 1

ISSN:0165-0513    

DOI:10.1002/recl.19730920808

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe sulfur‐carbon bond cleavage with alkali metals in liquid ammonia has been investigated in several heterocycles. Special attention has been paid to substituted 1,4‐thiazin‐3‐ones VIII in which the carbon‐sulfur bond is cleft selectively with formation of the dianion X. The protonation, alkylation and acylation of the alkenethiolates X and XI have been studied. Routes to the synthesis of 2,3‐dihydro‐4H‐1,4‐thiazine XIX and tetrahydro‐1,4‐thiazepine X

ISSN:0165-0513    

DOI:10.1002/recl.19730920809

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractTheS‐hydroxy, ‐amino and ‐mercapto alkylation of 2‐acetamidopropenethiolates II is described. Intramolecular cyclization of these functionalized alkenes to acetamido‐substituted 1,4‐oxathianes, 1,4‐dithiane, thiomorpholine, 1,4‐oxathiepane and 1,4‐dithiepane can be achieved in good yields in the presence of base or acid catalysts. The cyclization to 1,4‐oxathianes has been studied in detail and the configuration of the stereoisomers has been assigned on the basis

ISSN:0165-0513    

DOI:10.1002/recl.19730920810

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe 100 MHz PMR spectra of the diastereoisomers of 1,3,5‐tri(1‐hydroxy‐2,2‐dimethylpropyl)benzene (2) and 1,3,5‐tri(1‐hydroxy‐1,2,2‐trimethylpropyl)‐benzene (1) are discussed. The high barrier to rotation reported in the literature for the hydroxyalkyl groups of1is probably in error. A value of 9.5 kcal/mole at −77° has been determined for 1‐(1‐hydroxy‐1,2,2‐trimethylpropyl)‐3,4,5‐trimethoxybenzene (3) and the low temperature spectra of1indicate a value in the same range. The barrier to rotation for the hydroxyalkyl groups in2or in the 3,4,5‐trimethoxybenzene deri

ISSN:0165-0513    

DOI:10.1002/recl.19730920811

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY