摘要:

AbstractPairs of steroid 17(20),20‐allenes, epimeric at C(21), have been obtained by LiAlH4(D4)/AlCl3reduction of 17α/β‐hydroxy‐17β/α‐alkynyl steroids, confirmed by means of optical rotation differences and NMR spectroscopy. In all cases the reduction proved to be fully stereospecific, confirming thecis‐SN2′ mechanism, postulated in part II1.In addition, the NMR spectra of 17‐(trans‐1‐alkenyl) 17‐hydroxy compounds, obtained as by‐products or especially prepared, have been analysed. Finally the structure of a dideuterioallene, tentatively described as a 16β,21α‐dideuterio‐17(20),20‐allene in part III2, has been proved by full analysis of the 300 MHz s

ISSN:0165-0513    

DOI:10.1002/recl.19790981202

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractTreatment of the quinoidN,N‐dialkyl‐α‐(3,5di‐tert‐butyl‐2‐oxo‐3,5‐cyclohexadienylidene)‐α‐phenylacetamides 6 with boron trifluoride etherate generally gives rise to rearrangement into the γ‐lactones 3‐dialkylamino‐5,7‐di‐tert‐butyl‐3‐phenyl‐2,3‐dihydrobenzo[b]furan‐2‐ones11. In the case of the carboxamide7,N,N‐diethyl‐α‐(3,5‐di‐tert‐butyl‐6‐hydroxyphenyl)‐α‐oxoacetamide14is formed. The quinoidN,N‐diethyl‐α‐methylthio‐α‐(10,oxo‐9‐phenanthrenylidene)acetamide8is converted by boron trifluoride etherate into the γ‐lactone 3,3‐bis(methylthio)‐2,3‐dihydrophenanthro‐[9,10‐b]furan‐2‐one22and phenanthro[9,10‐b]furan‐2,3‐dione23. In the presence of alcohols, inte

ISSN:0165-0513    

DOI:10.1002/recl.19790981203

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractRate constants have been measured for the addition of sulphite ion and hydroxylamine on a series of sterically hindered cyclohexanones as well as for the decomposition of the bisulphite adducts. The observed differences in reactivity mau be regarded as resulting from the intervention of the “steric compression effect” due to the axial substituents. Calculated δΔG≠values confirm the existence of such an effect and the results are consistent with the intermediate formation of a “reactant‐like” transition state in th

ISSN:0165-0513    

DOI:10.1002/recl.19790981204

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe synthesis of β‐LPH‐(61–76) and β‐LPH‐(61–77) [i.e. α‐ and γ‐endorphin, respectively] by means of the fragment condensation approach is described.Several of the fragments leading to these two endorphins were also obtained as

ISSN:0165-0513    

DOI:10.1002/recl.19790981205

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractNew values for3JHHalong the C4′‐C5′ bond in nucleosides and nuclsotides are pro

ISSN:0165-0513    

DOI:10.1002/recl.19790981206

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19790981201

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY