Претраживање
Приказ резултата 11-20 од 42
Lead tetra-acetate oxidation of saturated aliphatic alcohols-V. Factors influencing the formation of cyclic ethers and carbonyl compounds
(Elsevier, 1966)
Factors influencing the relative rates of the homolytic and heterolytic processes in the lead tetra-acetate oxidation of unbranched primary and secondary aliphatic alcohols have been investigated, with a view to determine ...
The conformational equilibrium of 1,3-dichloro-5-methylcyclohexane
(Elsevier, 1981)
Two of the stereoisomers of the title compound were prepared and their dipole moments were measured. For the r-1,c-3-dichloro-t-5-methylcyclohexane, the free energy difference between conformers with axial-axial (aa) and ...
Organocatalyzed Tsuji-Trost reaction: a new method for the closure of five- and six-membered rings
(Oxford : Pergamon-Elsevier Science Ltd, 2009)
A combination of organotransition metal catalysis and organocatalysis allows for Tsuji-Trost 5-exo- and 6-exo-cyclizations of aldehydes. This transformation can also be accomplished as a catalytic asymmetric reaction, which ...
Studies of the regioselective ring-opening closing mode of functionally different thiazolidine type enaminones: en route to the synthesis of trithiaazapentalene derivatives
(Oxford : Pergamon-Elsevier Science Ltd, 2013)
Trithiaazapentalene derivatives were prepared by the reaction of 2-alkylidene-4-oxothiazolidines with Lawesson's reagent. They are classified as two structurally different trithiaazapentalene compounds that have different ...
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.
Photochemically induced mercuric oxide - iodine oxidation of some unsaturated steroid compounds
(Pergamon, 1994)
Photochemically induced HgO/I2 oxidation of cholest-5-en-3α-ol (6) and cholest-5-en-3β-ol (7) afforded (Scheme 3) products arising from the corresponding alkoxy radicals (12, 13 and 14a,b) and from attack of the I2O ...
Free-radical oxidative transformations of androst-4-ene-3β,9α,17β-triol 3,17-diacetate
(Tetrahedron, 1988)
The oxidation of androst-4-ene-3β,9α,17β-triol 3,17-diacetate (2) with lead tetraacetate resulted mainly In β-fragmentation of the C(9)-C(10) bond to give a mixture of 10α- and 10β-acetoxy-Δ4-unsaturated 9,10-seco-steroidal ...
Synthesis, biology, and modeling of a C-4 carbonyl C,D-seco-taxoid
(Oxford : Pergamon-Elsevier Science Ltd, 2006)
A C,D-seco-paclitaxel derivative 26 was prepared from taxine and tested for biological activity. Chemical reactivity of the seco-compounds proved to be substantially modified, with respects to taxoids. The corresponding ...
Fullerene bisadduct regioisomers containing an asymmetric diamide tether
(Oxford : Pergamon-Elsevier Science Ltd, 2017)
Four macrocyclic bis(pyrrolidino)fullerene regioisomers with e-edge, e-face, trans-4 and cis-2 addition patterns were synthesized from the corresponding monoadduct by Prato's cycloaddition in a yield of 50%, and fully ...
Synthesis and properties of bis(pyrrolidino)fullerenes bridged by a flexible alkyl-tether
(Oxford : Pergamon-Elsevier Science Ltd, 2015)
The one-pot bistycloaddition of alkyl-tethered diglycines to C-60 provided five series of bridged bis(pyrrolidino)fullerenes with good regioselectivity, giving mainly cis-2 and cis-3 products. An influence of the bridge ...