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Приказ резултата 1-10 од 44
Configuration and reactivity of ten-membered 5,10-seco-compounds obtained by fragmentation of 5-hydroxy-steroids
(Elsevier, 1966)
Assignment of configuration to the 1,10-double bond in the cis-trans isomeric 3β-acetoxy-5,10-seco-1,10-cholesten-5-ones has been achieved by means of NMR spectrometry. Some reactions of these new compounds have been studied ...
A novel procedure for the aromatization of ring a in 19-nortestosterone
(Elsevier, 1977)
A convenient, 40% overall yield synthesis of 2,3,17β-triacetoxy-1,3,5(10)-estratriene is described, which involves epoxidation of 19-nortestosterone and subsequent acetylation, lead tetra-acetate acetoxylation of the ...
pi-Annulation reactions of 4-thiazolidinone enaminones in the synthesis of fused bi- and tri-cyclic compounds
(Oxford : Pergamon-Elsevier Science Ltd, 2012)
The a-C position in 4-oxo thiazolidinones functions as one of the three possible nucleophilic sites in these molecules. We used the inherent reactivity of alpha-C of the exocyclic double bond (a so called push pull system) ...
endo-Mode cyclizations of vinylogous N-acyliminium ions as a route to the synthesis of condensed thiazolidines
(Oxford : Pergamon-Elsevier Science Ltd, 2011)
endo-Mode cyclizations of vinylogous N-acyliminium ions incorporating heteroatom-based nucleophiles have been examined as a route to the synthesis of condensed thiazolidines. The scope of these reactions and stereochemical ...
Reactions with lead tetraacetate-IV. Oxidation of saturated aliphatic alcohols-II; Alcohols of low molecular weight
(Elsevier, 1965)
The action of lead tetraacetate on ethanol, 1-propanol, 2-propanol and 2-butanol has been studied under various experimental conditions, and it was found that the tetravalent lead compound reacts with alcohols in ways not ...
Regioselective synthesis of 1,3-thiazines by sequential 4-oxothiazolidine to 1,2-dithiole to 1,3-thiazine transformations: role of intramolecular non-bonded S/O interactions
(Elsevier, 2007)
A new synthetic approach to 2,3-dihydro-4H-1,3-thiazine derivatives based upon reductive rearrangement of 1,2-dithiole-3-ylidene thiones has been developed. In turn, the 1,2-dithiole derivatives were prepared by an efficient ...
Opening of steroid ring a by means of lead tetraacetate
(Elsevier, 1964)
The lead tetraacetate oxidation of cholestan-1β-ol and cholestan-1α-ol in benzene solution did not afford cyclic ethers but resulted, in major part, in the opening of ring A with formation of 1,10-seco-aldehydes. In addition, ...
The reaction of lead tetra-acetate with some unbranched α,ω-diols
(Elsevier, 1969)
Unbranched α,ω-diols are mainly converted by means of lead tetra-acetate in refluxing benzene to the corresponding ethers of di-α-tetrahydrofuryl, di-α-tetrahydropyryl and/or α-tetrahydrofuryl-α′-tetrahydropyryl type. Thus, ...
A novel pimara-8(9),15-diene from lycopus europaeus
(Pergamon Press, 1985)
Identification of a novel trioxygenated Δ8(9),15_ pimaric acid methyl ester from plant species Lycopus europaeus by means of two-dimensional 1H NMR spectroscopy (COSY and NOESY) is reported. © 1985.
Lead tetraacetate oxidation of saturated aliphatic alcohols-IV. The formation of six-membered cyclic ethers
(Elsevier, 1965)
The lead tetraacetate oxidation of saturated aliphatic alcohols, with structures which do not permit 1,5-cyclization, gave tetrahydropyran derivatives in yields not exceeding 16%. The formation of a small amount of the ...