ISSN:0165-0513    

DOI:10.1002/recl.19821011201

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe luminescence properties of the following decatungstates have been investigated: X9LnW10O36(X = tetra‐n‐butylammonium or brucinium; Ln = Sm, Eu, Dy). Due to the large X ions, the separation between the lanthanide ions is very large. Consequently no interaction between these ions occurs, not even in the case of Sm and Dy. The tetra‐n‐butylammonium salts contain a small number of alkali metal ions. The emission of Eu3+has been used to analyse the composition in more detail. The brucinium salts do not luminesce efficiently upon tungstate excitation, since the excitation energy is lost, for the greater part, in the brucini

ISSN:0165-0513    

DOI:10.1002/recl.19821011202

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe1H and13C spectra of mianserin, 1, reveal a perfectly chair‐formed piperazine ring having an equatorial N‐methyl group, a trans‐piperazine‐dihydroazepine ring junction and a nonplanar dihydroazepine ring. The1H spectra of the 10‐hydroxymianserin derivatives 2 and 3 show that their dihydroazepine ring conformation is similar and that C(10) ‐ the upper bridge ‐ is twisted towards the N

ISSN:0165-0513    

DOI:10.1002/recl.19821011203

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractProcedures are described involving the condensation of l‐(hydroxymethyl)pyrazole (1a) and l‐(hydroxymethyl)‐3,5‐dimethylpyrazole (1b) with the following amines (products given in parentheses): ethylamine (2a and 2b), aniline (3a and 3b), N,N′‐dimethyl‐ l,2‐ethanediamine (4a and 4b), 1,2‐ethanediamine (6a and 6b), diethylenetriamine (7a and 7b), triethylenetetramine (8a and 8b) and ammonia (9a and 9b). All amine hydrogens are completely substituted by pyrazol‐1‐ylmethyl groups (compounds 2a‐9a) or (3,5‐dimethylpyrazol‐1‐yl)methyl groups (compounds 2b‐9b wi

ISSN:0165-0513    

DOI:10.1002/recl.19821011204

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe annelation reaction between l,2,3,6‐tetrahydro‐1‐phenyl‐4‐(1‐pyrrolidinyl)phosphorin 1‐oxide (10) and 2,2‐bis(chloromethyl)acetophenone (7) leads to two stereoisomeric 7‐benzoyl‐3‐phenyl‐3‐phosphabicyclo[3.3.1]nonan‐9‐one 3‐oxides 11a and 11b. Their difference resides in the configuration at phosphorus, which also determines the conformation of the bicyclononane skeleton, as revealed from the crystal structures. Reduction of the two keto functions in 11a with NaBH4to give 12a, followed by HSiCl3reduction to the phosphine 13a and acid‐catalyzed ring closure, yields the title compound (4a), the structure of which was corroborated by an X‐ray crystal structure determination. Interestingly, the same sequence of reactions converts 11b into a 3.3 : 1 mixture of 4a and 4b; presumably, inversion of configuration at phosphorus occurs in the

ISSN:0165-0513    

DOI:10.1002/recl.19821011205

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe synthesis is described of several peptides containing the sequence Phe‐Met. In order to limit enzymatic degradation and to restrict the number of possible conformations they were cyclized with variable ring size. Some unexpected side‐reactions were encountered during the synthesis of the linear precursors: partial cleavage of the active ester during removal of the Bocprotecting group, partial cleavage of the Gly‐Gly peptide bond during hydrazinolysis of an ester function and failure to obtain the p‐nitrophenyl ester of Boc‐Phe‐Met‐Gly‐Gly‐OH via the DCC method. Diphenyl phosphoroazidate was finally used for the cyclization of several linear peptides. Some results of behavioural activity and metabolic stabil

ISSN:0165-0513    

DOI:10.1002/recl.19821011206

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe preparation of Diels‐Alder adducts of (‐)‐thebaine and ethyl acrylate is described. Hydrolysis of the major adduct gave the 7α‐carboxylic acid which was coupled with the ethyl esters of L‐leucine, L‐phenylalanyl‐L‐leucine and glycyl‐L‐phenylalanyl‐L‐leucine, respectively, three peptide segments derived from the endogenous opiate, leucine‐enkephalin. These compounds, as well as the 7β‐ethoxycarbonyl isomer, were O‐demethylated to give the corresponding 3,6‐dihydro‐xymorphinan derivatives. N‐(6,14‐endo‐Etheno‐6,7,8,14‐tetrahydrothebaine‐7α‐carbonyl)‐L‐phenylalanyl‐L‐leucine ethyl ester and its 7,8‐dihydromorphine analogue were reduced to the corresponding leucinols.Pharmacological screeningDr. A. E. Jacobson, National Institutes of Health, Bethesda, Maryland, U.S.A.showed that several of these compounds are morphine‐like analgesics, notably compound11, N‐(6,14‐

ISSN:0165-0513    

DOI:10.1002/recl.19821011207

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe title compound was prepared from trimethylacetyl chloride and sodium formate in the presence of 18‐crown‐6. The mixed anhydride proved to be a very useful reagent for the N‐formylation of amines. Even amines which are unstable when deprotonated can be formy

ISSN:0165-0513    

DOI:10.1002/recl.19821011208

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY