摘要:

AbstractThe synthesis of 3‐phenyl‐2‐oxa‐1,5‐pentanediol diacetate is given. This compound offers a new route to the preparation of cinnam

ISSN:0165-0513    

DOI:10.1002/recl.19590780702

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

Abstract1Of several ions tested, only Fe+3, Cu+2and Al+3catalysed the decarboxylation of α‐acetolactic acid at pH 4.8.2At pH 2.2, only Fe+3and Cu+2were active.3Fe+3and Cu+2were shown to form complexes with α‐acetolactic acid.4Fe+3and Cu+2not only decarboxylated but also oxidized α‐acetolactic acid, with, as a result, formation of diacetyl.5Decarboxylation of α‐acetolactic acid by these ions is compatible with the mechanism suggested byMartell and Calvin.6α‐Acetolactic acid is subject to autoxidation. 2‐Butene‐2,3‐diol may be an

ISSN:0165-0513    

DOI:10.1002/recl.19590780703

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractDipeptides are obtained optically pure and in good yield by boiling equivalent amounts of N‐acylamino‐acids and amino‐ester hydrochlorides with ethoxyethyne in ethyl acetate containing 0.5% of water.For the preparation of higher peptides it is preferable to add the amino‐component not as hydrochloride but as free ester, because otherwise partial racemisation may occur.By means of this method the hexapeptide, pro‐val‐lys‐val‐tyr‐pro, a sequence present in β‐corticotropi

ISSN:0165-0513    

DOI:10.1002/recl.19590780704

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19590780705

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractPolarographic maxima have been studied in the light of the electrocapillary curves produced by the successive addition of the maximum suppressor. An interesting agreement has been noticed between the minimum concentration of the suppressor required to eliminate the polarographic maximum completely and the point of greatest negative slope in the interfacial‐tension concentration curve. The results show that polarographic maxima are eliminated when the adsorption of the maximum suppressor on the mercury‐solution interface reaches its maximum va

ISSN:0165-0513    

DOI:10.1002/recl.19590780706

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractLa N‐tritylation des diesters glutamiques, en protégeant la fonction ester en α, permet d'accéder au N‐trityl‐L‐glutamate d'α‐(β'‐chloro éthyle). Le traitement usuel par la triméthylamine suivi de la détritylation en acide acétique aqueux conduità l'α‐L‐glutamyl choline qu'on isole sous forme d'iodure

ISSN:0165-0513    

DOI:10.1002/recl.19590780707

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractLes arènesulfonylsulfates de méthyle sont obtenus soit par addition d'anhydride sulfurique sur la molécule d'un arènesulfonate de méthyle, soit par dismutation entre un acide arènesulfonique et le pyrosulfate de méthyle. Ces nouveaux dérivés réagissent aisément avec des composés aromatiques pour conduire aux sulfones, symétriques ou non, avec des rende

ISSN:0165-0513    

DOI:10.1002/recl.19590780708

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractChlorination of 4‐acetylaminobenzoic acid (III) afforded 4‐acetylamino‐3,5‐dichlorobenzoic acid (IV, m.p. 237‐238°), which could be saponified easily to 4‐amino‐3,5‐dichlorobenzoic acid (II, m.p. 290°). Direct chlorination of 4‐aminobenzoic acid (I) in a mixture of glacial acetic acid and hydrochloric acid afforded 3,4,4,6,6‐pentachloro‐1‐cyclohexen‐5‐one‐2‐carboxylic acid (V, m.p. 178‐180°), a compound already obtained byZinckeby the chlorination of 4‐hydroxybenzoic acid (VI). Compounds with a higher content of chlorine could be prepared by the chlorination of the methyl ester of I (VIII). The reaction carried out in a neutral medium led to the nitrogen containing compound IX with m.p. 151‐153° and gross formula C8H5NO2Cl8to which the structure of a methyl 1,2,3,3,5,5,6‐heptachloro‐4‐chloriminocyclohexane‐1‐carboxylate was attributed. Reduction with stannous chloride converted IX into methyl 4‐amino‐3,5‐dichlorobenzoate (X), which can be used as a starting product for IX. Chlorination of VIII in a mixture of glacial acetic acid and hydrochloric acid yielded a compound XI with m.p. 129‐131° and gross formula C8H5O3Cl7as the main reaction product to which the structure of a methyl 1,2,3,3,5,5,6‐heptachlorocyclohexan‐4‐one‐1‐carboxylate has been attributed. Acid hydrolysis converted IX into XI. From the same reaction mixture two other stereo‐isomers of XI also were isolated, be it in minor quantities (XII m.p. 140–142°, XIII m.p. 213‐215°). The stereoisomerism of the three compounds is caused by the different spatial arrangement of the chlorine atoms attached to carbon atoms 1, 2 and 6. Reduction converted the three isomers into methyl 3,5‐dichloro‐4‐hydroxybenzoate (XIV). Chlorination of the methyl esters of VI and XIV also afforded amounts of XI. A fourth chlorination product could be isolated from the reaction mixture of VIII, viz. a compound with m.p. 199‐200° and gross formula C8H6O4Cl6(XVI). Reduction with stannous chloride converted it into a compound XVII with m.p. 121‐122° and gross formula C8H8O4Cl2. Both compounds contain an extra hydroxyl group. Lack of material prevented further establis

ISSN:0165-0513    

DOI:10.1002/recl.19590780709

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe preparation of dimethyl‐, diethyl‐, dipropyl‐, dibutyl‐, and di‐isobutylphosphinic chlorides from bi(dialkylphosphinothioyl) compounds, mentioned in the first part of this paper1, is described (Table I).In the reactions of alkylmagnesium halides with PSCl3, where several phosphinic acidic reaction products are formed [for instance (R2PS)2, R2PSCl, and R2P(S)SH], the combined reaction products from each Grignard reaction are oxidized and the crude phosphinic acids converted into the phosphinic chlorides. In this way dipropyl‐, di‐isopropyl‐, dibutyl‐, di‐isobutyl, di‐s‐butyl‐, and dipentylphosphinic chlorides are obtained

ISSN:0165-0513    

DOI:10.1002/recl.19590780710

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

Abstractβ‐Lactams VII are formed when ethoxyalkynes II are slowly added to boiling solutions of aromatic imines VI in xylene. In all probability aldoketenes III are intermediate products. The yields are moderate to go

ISSN:0165-0513    

DOI:10.1002/recl.19590780711

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY