0000000000327993
AUTHOR
J. R. Pedro
ChemInform Abstract: The Reduction of α,β-Unsaturated Nitriles and α- Halonitriles with Sodium Hydrogen Telluride.
Abstract Sodium hydrogen telluride reacts chemoselectively with α,β-unsaturated nitriles and α-halonitriles linked to aromatic and aliphatic substituents to give the corresponding saturated nitriles with good yields.
Preparation of 2,3-seco-5α-cholestane-2,3-diol and 4α-methyl-2,3-seco-5α-cholestane-2,3-diol and its reactions with o-nitrophenyl selenocyanate
The reaction of 2,3-seco-5 alpha-cholestane-2,3-diol and 4 alpha-methyl-2,3-seco-5 alpha-cholestane-2,3-diol with o-nitrophenyl selenocyanate was studied. The diols were synthesized from cholesterol.
Alkane oxidation by a carboxylate-bridged dimanganese(III) complex
[EN] A new manganese( III) oxamato dimer possesing an unprecedented Mn-2(mu -O2CR)(mu -OH2. . .O2CR) core has been synthesised, structurally and magnetically characterised, and used as a catalyst for the oxidation of alkanes to alcohols and ketones by (BuO2H)-O-t and O-2 in CH2Cl2 at rt.
Aerobic epoxidation of olefins catalysed by square-planar cobalt(III) complexes of bis-N,N′-disubstituted oxamides and related ligands
The new square-planar nickel(II) complexes of o-phenylenebis(N′-methyloxamidate) and related ligands catalyse the aerobic epoxidation of olefins with co-oxidation of pivalaldehyde; the modulation of catalytic activity by substituents along this series of metal complexes points out the role of high-valent nicke(IV)-oxo species as the putative intermediate in these oxygen atom transfer reactions.
Two guaianolides from Centaurea collina
Abstract Two guaianolides isolated from the aerial parts of Centaurea collina were identified as 3β-hydroxy-8α-epoxymethylacriloiloxy-4(15),10(14),11(13 and its 11β,13-dihydro derivative by spectroscopic methods.
Regio- and stereoselective oxyfunctionalization at C-1 and C-5 in sesquiterpene guaianolides
Abstract The regio- and stereoselective functionalization at C-1 and C-5 positions in a guaiane skeleton by allylic hydroxylation are described. The stereochemistry of the resulting compounds are identical to those of the majority of natural 1- and 5-hydroxy-guaianolides.
Sesquiterpene lactones from Centaurea alba and C. conifera
Abstract The aerial parts of Centaurea alba yielded five know germacranolides: salonitenolide, 11β, 13-dihydrosalonitenolide, salonitenolide 8- O -(4′-acetoxy-5′-hydroxy)-angelate, cnicin 4′-O-acetate and cnicin. The aerial parts of C. conifera yielded loliolide, 1β,6α-dihydroxy-4(15)-eudesmene, chlorojanerin, chlorohyssopifolin A (centaurepensin) and its C-17 epimer. The latter compound is described for the first time.
ChemInform Abstract: The Synthesis of Bioactive Sesquiterpenes from Santonin
Abstract This article reviews the literature published in the last decade dealing with the transformation of α-santonin into bioactive or potentially bioactive sesquiterpenes. A number of syntheses starting from 8α-hydroxysantonin (artemisin) have also been included. Special emphasis has been placed on synthesized products that show biological activity. Major advances in this field include the application of new reagents and methodologies for the structural modification of the santonin skeleton and functionality, and its transformation into other sesquiterpenes, especially sesquiterpene lactones. The review has been organised into five parts: 1. Introduction: An overview of the structure an…
Catalytic aerobic oxidative decarboxylation of α-hydroxy-acids. Methyl mandelate as a benzoyl anion equivalent
Abstract The monomeric square-planar cobalt(III) complex of bis- N,N ′-disubstituted oxamides catalyses the oxidative decarboxylation of α-hydroxy acids with molecular oxygen/pivalaldehyde with very good yields. This reaction offers an interesting alternative in the use of methyl mandelate as a convenient benzoyl anion equivalent.
ChemInform Abstract: Catalytic Aerobic Oxidative Decarboxylation of α-Hydroxy Acids. Methyl Mandelate as a Benzoyl Anion Equivalent.
Abstract The monomeric square-planar cobalt(III) complex of bis- N,N ′-disubstituted oxamides catalyses the oxidative decarboxylation of α-hydroxy acids with molecular oxygen/pivalaldehyde with very good yields. This reaction offers an interesting alternative in the use of methyl mandelate as a convenient benzoyl anion equivalent.
The Synthesis of Bioactive Sesquiterpenes from Santonin
Abstract This article reviews the literature published in the last decade dealing with the transformation of α-santonin into bioactive or potentially bioactive sesquiterpenes. A number of syntheses starting from 8α-hydroxysantonin (artemisin) have also been included. Special emphasis has been placed on synthesized products that show biological activity. Major advances in this field include the application of new reagents and methodologies for the structural modification of the santonin skeleton and functionality, and its transformation into other sesquiterpenes, especially sesquiterpene lactones. The review has been organised into five parts: 1. Introduction: An overview of the structure an…
Oxidation of N-Acyl-pyrrolidones to Imides with CrO3·3,5-dimethylpyrazole
Abstract N -Acyl-pyrrolidones are easily obtained by treatment of N -acyl-pyrrolidines with CrO 3 ·3,5-dimethylpyrazole complex (CrO 3 ·3,5-DMP) at room temperature.
Synthesis of 9-oxyfunctionalized eudesmanes from artemisin
Abstract Artemisin ( 1 ) was transformed into two natural sesquiterpenoids 2 and 3 in a sequence which involves functionality transfer from C 8 to C 9 and further elaboration of the A ring and the lactone moiety.