摘要:

AbstractThe β‐carbonyl group of the unsaturated β‐oxo esters1and2can be selectively reduced using sodium tetrahydroborate in methanol to give the γ‐ and δ‐unsaturated β‐hydroxy esters3and4, respectively. The unsaturated 1,3‐diols5and6were obtained by reduction of the β‐carbonyl group as well as the ester function of unsaturated β‐oxo esters1and2using lithium tetrahydroaluminate. For the conversion of γ‐unsaturated β‐oxo esters1, with R1= H and R2= aryl, into the corresponding unsaturated diols5, hydrobis(2‐methylpropyl)aluminum was used to preven

ISSN:0165-0513    

DOI:10.1002/recl.19851041102

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractFour retinals labelled at positions 5, 6, 7 and 18 with13C were obtained via simple schemes involving only a few steps with>98% chemical purity and 92%13C incorporation. (5‐13C)Retinal was obtained in 26% yield from K13CN. (6‐13C)‐ and (7‐13C)Retinal were obtained in 37% yield from (2‐13C)‐ and (1‐13C)acetonitrile, respectively, while (18‐13C)retinal was obtained in 8 steps and 4% yield starting from13CH3I. Their13C‐1H and13C‐13C NMR coupling consta

ISSN:0165-0513    

DOI:10.1002/recl.19851041103

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractThe reaction of the 3,3′,5,5′‐tetramethyl‐2,2′‐pyrromethen‐1,1′‐BF2complex with chlorosulfonic acid and its subsequent neutralisation with sodium bicarbonate yields the titled compound1, which, in addition to appropriate thermal and photochemical stability, possesses excellent fluorescent properties. As a preliminary assay of its potential usefulness as a fluorescent probe in medical and biological research, the chemical was administered intravenously to rats and possible signs of toxicity were recorded. The rats showed no apparent detrimental effects and excreted the compound in the urine within three hours. In tests in whichSalmonellaandE. colistrains were used as indicators of genotoxicity, no mutagenic effe

ISSN:0165-0513    

DOI:10.1002/recl.19851041104

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

Abstract3,4,6‐Tri‐O‐acetyl‐2‐azido‐2‐deoxy‐α‐D‐glucopyranosyl bromide was converted in four steps into allyl 2‐azido‐3‐O‐benzoyl‐2‐deoxy‐4,6‐O‐(4‐methoxybenzylidene)‐β‐D‐glucopyranoside. Treatment of the latter with sodium cyanoborohydride and hydrogen chloride in oxolane (THF) gave allyl 2‐azido‐3‐O‐benzoyl‐2‐deoxy‐6‐O‐(4‐methoxybenzyl)‐(β‐D‐glucopyranoside. Further, 3,4,6‐tri‐O‐acetyl‐2‐azido‐2‐deoxy‐α‐D‐galactopyranosyl bromide was converted in five steps into allyl 2‐azido‐3‐O‐benzoyl‐2‐deoxy‐6‐O‐(4‐methoxybenzyl)‐β‐D galactopyranoside. The 4‐methox

ISSN:0165-0513    

DOI:10.1002/recl.19851041105

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractCyclic voltammetry and preparative controlled potential electrolysis show that the 9‐phenyl‐10‐methyl‐acridinium/acridan (AcPh+/AcPhH) redox couple can be cycled electrochemically between the oxidized (AcPh+) and reduced states (AcPhH) without any apparent side‐reaction. The 9‐phenyl‐10‐methyl‐acridanyl radical (AcPh•) was identified as a first intermediate in the electrochemical reduction of AcPh+by cyclic voltammetry as well as by electronic absorption and ESR spectroscopy. In contrast to other acridanyl and related dihydropyridyl radicals, AcPh•shows no tendency to undergo dimerization. In aprotic media, AcPh•is shown to undergo a second reversible one‐electron reduction to yield AcPh−, which is, even in these media readily protonated to give AcPhH. The stability of these intermediates seems to be the major factor responsible for the clean electrochemical interconversion of the AcPh+/AcPhH redox couple. The implementation of this redox couple as part of photo‐electrochemical energy co

ISSN:0165-0513    

DOI:10.1002/recl.19851041106

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractA number of 1‐aminopurinium mesitylenesulfonates have been prepared in reasonable to good yields by treatment of the corresponding purines withO‐(mesitylenesulfonyl)hydroxylamine. The structure of these salts has been established by means of1H and13C NMR spectroscopy, using, as diagnostic tools, theJ(H‐2, H‐6),3J(C‐2, H‐6) and3J(C‐6, H‐2) coupling constants for compounds which are unsubstituted at positions 2 and 6 and the13C Δδ values of C‐2 or C‐6 and C‐8 for C‐2 or C‐6

ISSN:0165-0513    

DOI:10.1002/recl.19851041107

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19851041108

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractA synthesis of theE‐ andZ‐isomers of optically pure (S)‐fecapentaene‐12 is described. The method is based on the chromatographic separation of diastereomeric adducts, formed as intermediates in the Horner‐Wittig reaction of an all‐transundecatetraenal with a chiral phos

ISSN:0165-0513    

DOI:10.1002/recl.19851041109

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19851041101

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY