871-91-0Relevant articles and documents
Synthesis of boron-containing cholesterol derivatives for incorporation into unilamellar liposomes and evaluation as potential agents for BNCT
Feakes, Debra A.,Spinler, Jennifer K.,Harris, Fred R.
, p. 11177 - 11186 (1999)
Four carborane-containing derivatives of cholesterol were prepared for incorporation into the bilayer of unilamellar liposomes and evaluation as potential agents for boron neutron capture therapy. The derivatives enable the evaluation of the linker moiety and the type of carborane head group on the bilayer stability and ultimate in vivo tumor specificity.
18-iodooctadeca-(8Z,11Z)-dienoic acid as useful intermediate for the synthesis of special lipoxygenase substrates bearing bulky substituents at the ω-position
Ivanov, Igor V.,Groza, Nataliya V.,Romanov, Stepan G.,Kuhn, Hartmut,Myagkova, Galina I.
, p. 553 - 556 (2000)
18-Iodooctadeca-(8Z, 11Z)-dienoic acid (7) was synthesized in five steps starting from methyl 10-bromodec-7-ynoate (2) in an overall yield of 53%. The synthetic procedure involves Cu(I)-catalyzed cross-coupling of propargylic bromide 2 with 7-octyn-1-ol (3), followed by hydrogenation of the coupling product 4 to Z,Z-diene 5 on Lindlar's catalyst and subsequent substitution of the OH- group of 5 with iodine. Coupling of the resulting iodide 7 with low- order organic cuprates [t-Bu2CuLi or (PhCH2)2CuMgCl] leads to 19,19- dimethyl-eicosa-(8Z, 11Z)-dienoic acid (1a) and 19-phenylnonadeca-(8Z, 11Z)- dienoic acid (1b), respectively. (C) 2000 Elsevier Science Ltd.
Total synthesis of the cytotoxic enehydrazide natural products hydrazidomycins A and B by a carbazate addition/peterson olefination approach
Beveridge, Ramsay E.,Batey, Robert A.
, p. 3086 - 3089 (2013)
The first total syntheses of two natural antitumor enehydrazide compounds (hydrazidomycins A and B) and a related positional isomer of hydrazidomycin B (elaiomycin B) have been accomplished in a rapid and stereocontrolled fashion using a Peterson elimination approach. A regioselective silyl epoxide ring opening reaction with Boc-carbazate followed by base-mediated Peterson siloxide elimination stereospecifically installed the key Z-enehydrazide functionality. The use of Boc-carbazate allowed for the differential functionalization of the hydrazide nitrogens.
Click-Connected 2-(Hydroxyimino)aldehydes for the Design of UV-Responsive Functional Molecules
Carbonaro, Linda,Cort, Antonella Dalla,D'Acunzo, Francesca,Di Sabato, Antonio,Filippini, Dario,Gentili, Patrizia,Leonelli, Francesca,Mancini, Laura
supporting information, p. 289 - 294 (2020/12/17)
Click chemistry is used to functionalize simple lipophilic and water-soluble molecules, a complex PEGylated phospholipid (DSPE-PEG2000), and two benzylic substrates with the 2-(hydroxyimino)aldehyde (HIA) group. To this end, two terminal alkynes bearing the HIA moiety were synthesized and coupled to different azides through copper(I)-catalyzed azide alkyne cycloaddition (CuAAC). Norrish–Yang photoisomerization (λ= 365 nm, LED source) is successfully obtained, with no interference by the triazole linker, except when the forbidden n-π* carbonyl transition is screened by a remote substituent such as salicylaldehyde. UV-Vis spectrometry suggests a specific interaction of HIAs with Cu(II), whereas no such evidence is found with Cu(I). We thereby show that the CuAAC methodology can be used successfully to obtain HIA-based UV-responsive hydrophilic or lipophilic ligands, phospholipidic components for the construction of liposomes, and macrocycle precursors.
Catalysis of Michael Additions by Covalently Modified G-Quadruplex DNA
Dey, Surjendu,Rühl, Carmen L.,J?schke, Andres
, p. 12162 - 12170 (2017/09/14)
Enantioselective catalysis utilizing G-quadruplex DNA-based artificial metalloenzymes has emerged as a new approach in the field of aqueous-phase homogeneous catalysis. Recently, a catalytic asymmetric Michael addition employing a covalently modified G-quadruplex in combination with CuII ions has been reported. Here we assess, by systematic chemical variation and using various spectrometric techniques, a variety of parameters that govern rate acceleration and stereoselectivity of the reaction, such as the position of modification, the topology of the quadruplex, the nature of the ligand, the length of the linker between ligand and DNA, the chemical identity of monovalent ions and transition metal complexes. The DNA quadruplex modified at position 10 (dU10) with hexynyl-linked bpy ligand showed twice the initial reaction rate as compared with the DNA strand derivatized at position 12 (dU12). The strikingly different dependence of the stereoselectivity on the linker length, and their different spectroscopic properties indicate large differences in the architecture of the catalytic centers between the dU10-derivatized and the dU12-modified quadruplexes. Upon addition of CuII, both types of bpy-derivatized DNA strands form defined 1:1 Cu–DNA complexes stable enough for mass spectrometric analysis, while the underivatized strands exhibit weak and unspecific binding, correlated with much lower catalytic rate acceleration. Both dU10- and dU12-derivatized quadruplexes could be reused ten times without reduction of stereoselectivity.
Total Synthesis and Structural Elucidation of Two Unusual Non-Methylene-Interrupted Fatty Acids in Ovaries of the Limpet Cellana toreuma
Shimada, Kazuaki,Sugawara, Ayako,Korenaga, Toshinobu,Kawashima, Hideki
, p. 1019 - 1032 (2017/10/07)
In our previous study, unusual odd-numbered dienoic acids with a terminal olefin were found as minor components in ovaries of the Japanese limpet Cellana toreuma, and the synthetic interests have been focused onto their structural confirmation and the inspection into their potential biological activity. Here, we describe an efficient and stereoselective total synthesis of two new unusual dienoic acids, 19:2?7,18 and 21:2?7,20, through a common pathway involving the strategic combination of alkyne-zipper reaction and Lindlar hydrogenation for the construction of their unique carbon chains. In our synthetic study, 2-propyn-1-ol was at first subjected to alkylation and alkyne-zipper reaction to form the two fragments, and the subsequent carbon chain elongation was achieved by the usual coupling reaction to obtain the C-19 and C-21 products bearing an internal acetylenic group. Then, the internal acetylenic group of these products was subjected to Lindlar hydrogenation to form a Z-alkenyl moiety, and the subsequent deprotection of the products was carried out under an acidic condition without isomerization of the internal Z-alkenyl group. Total synthesis of target fatty acids, 19:2?7,18 and 21:2?7,20, was finally accomplished by two-step oxidation of the resulting alcohols into carboxylic acids in a highly chemoselective manner, and the structures of these unusual natural fatty acids were finally elucidated by identifying the GC–MS spectra of the methyl esters of authentic and synthetic fatty acids.
