147356-77-2Relevant articles and documents
Additional vinyl ketones and their pyranyl ketones in gonyleptid harvestmen (Arachnida: Opiliones) suggest these metabolites are widespread in this family
Wouters, Felipe C.,Rocha, Daniele F. O.,Goncalves, Caroline C. S.,MacHado, Glauco,Marsaioli, Anita J.
, p. 1559 - 1564 (2013)
Four species of gonyleptid harvestmen, Acanthogonyleptes pulcher, Gonyleptes saprophilus (Gonyleptinae), Sodreana barbiellini, and Sodreana leprevosti (Sodreaninae), were examined by GC-MS and 1H NMR. All of these species release vinyl ketones, and three of them produce the corresponding pyranyl ketones, which are presumed hetero-Diels-Alder (HDA) dimers. The vinyl ketones 5-methyl-1-hexen-3-one, rac-4-methyl-1-hexen-3-one, and (S)-4-methyl-1-hexen-3-one were synthesized. Natural 4-methyl-1-hexen-3-one is present as a single stereoisomer and has the R-configuration. Vinyl ketone dimers (HDA dimers) were also observed in the scent gland exudate and characterized by HRMS, 13C NMR, and 1H NMR chemical shifts of the pyranyl moiety.
Synthesis and evaluation of an Iejimalide-archazolid chimera
Moulin, Emilie,Nevado, Cristina,Gagnepain, Julien,Kelter, Gerhard,Fiebig, Heinz-Herbert,Fürstner, Alois
, p. 6421 - 6428 (2010)
Even though the macrolides of the iejimalide family are of marine origin, whereas those of the archazolid series derive from terrestrial myxobacteria, a comparison of their constitution, stereochemistry, and biological activity suggests that these natural products are close structural and functional relatives. Guided by this perception, compound 5 was prepared, which hybridizes the macrolactone core of iejimalide B (2) with the tail of archazolid A (3). The cytotoxicity profile of this chimera, as determined with a panel of 12 human cancer cell lines, corresponds to that of the parent compound 2, although its potency is lower. This outcome may be interpreted on the basis of molecular dynamics calculations, which suggest that the low energy conformations of 2 and 5 are similar but the energetic barriers between the relevant conformers are distinctly higher for the hybrid structure. The synthesis of 5 hinged on a regioselective functionalization of 2,4-dibromothiazole 6, a highly selective CBS-reduction of ketone 8, a Suzuki cross coupling of vinyl boronate 17 with the elaborate alkenyl iodide 16, and a productive closure of the macrocycle by RCM, which requires the selective activation of two out of eight double bonds present in the cyclization precursor 20 by the second-generation Grubbs catalyst 21.
Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
Zhang, Xiao,Rovis, Tomislav
supporting information, p. 21211 - 21217 (2021/12/27)
Oximes are valuable synthetic intermediates for the preparation of a variety of functional groups. To date, the stereoselective synthesis of oximes remains a major challenge, as most current synthetic methods either provide mixtures of E and Z isomers or furnish the thermodynamically preferred E isomer. Herein we report a mild and general method to achieve Z isomers of aryl oximes by photoisomerization of oximes via visible-light-mediated energy transfer (EnT) catalysis. Facile access to (Z)-oximes provides opportunities to achieve regio- and chemoselectivity complementary to those of widely used transformations employing oxime starting materials. We show an enhanced one-pot protocol for photocatalyzed oxime isomerization and subsequent Beckmann rearrangement that enables novel reactivity with alkyl groups migrating preferentially over aryl groups, reversing the regioselectivity of the traditional Beckmann reaction. Chemodivergent N- or O- cyclizations of alkenyl oximes are also demonstrated, leading to nitrones or cyclic oxime ethers, respectively.
Synthesis of new cyclazines and 4,5-diaryl-1 H -pyrrol-3(2 H)-one units in discoipyrroles from indolizinone-DMAD cycloadducts
Kurian, Jais,Kannoth M, Muraleedharan
, p. 8832 - 8848 (2019/10/22)
The reaction of indolizinones with dimethyl acetylenedicarboxylate gave direct access to 3′,8a-dihydrocyclopenta[hi]indolizin-8a-ol and 1H-pyrrol-3(2H)-one in good yields. The former skeleton is a precursor to cyclazines with nitrogen on the periphery, a hitherto un-accessed 10-π system. Their formation involves initial [4 + 2] or [8 + 2] modes of cycloadditions; the retro-Diels Alder reaction of the [4 + 2] cycloadduct leads to 1H-pyrrol-3(2H)-one, whereas [8 + 2] addition followed by π-reorganization leads to the azatricyle. Analysis of substituent effects on product distribution showed that electron donating groups on the C3-aryl ring promote the formation of the azatricycle preponderantly. Treatment of one of these azatricycles (3c) with HBF4 led to the formation of the corresponding 10e-aromatic species which was detected by NMR spectroscopy. In addition, formation of the 1H-pyrrol-3(2H)-one skeleton through the normal retro-Diels Alder pathway was employed in the total synthesis of Discoipyrrole C, which is a new lead against lung cancer.
Differential induction of cytoplasmic vacuolization and methuosis by novel 2-indolyl-substituted pyridinylpropenones
Trabbic, Christopher J.,Dietsch, Heather M.,Alexander, Evan M.,Nagy, Peter I.,Robinson, Michael W.,Overmeyer, Jean H.,Maltese, William A.,Erhardt, Paul W.
supporting information, p. 73 - 77 (2014/02/14)
Because many cancers harbor mutations that confer resistance to apoptosis, there is a need for therapeutic agents that can trigger alternative forms of cell death. Methuosis is a novel form of nonapoptotic cell death characterized by accumulation of vacuo
Chiral silver phosphate catalyzed transformation of ortho-alkynylaryl ketones into 1H-isochromene derivatives through an intramolecular-cyclization/ enantioselective-reduction sequence
Terada, Masahiro,Li, Feng,Toda, Yasunori
supporting information, p. 235 - 239 (2014/01/17)
The transformation of ortho-alkynylaryl ketones through a cyclization/enantioselective-reduction sequence in the presence of a chiral silver phosphate catalyst afforded 1H-isochromene derivatives in high yield with fairly good to high enantioselectivity. An asymmetric synthesis of the 9-oxabicyclo[3.3.1]nona-2,6-diene framework, which has been found in some biologically active molecules, is presented as a demonstration of the synthetic utility of this method. Dependent on its other half: The title reaction of ortho-alkynylaryl ketones in the presence of a silver catalyst with a chiral counteranion afforded 1H-isochromene derivatives in high yield with good to high enantioselectivity (see scheme; R1=alkyl, aryl; R2=aryl; R3=H, F). An asymmetric synthesis of the 9-oxabicyclo[3.3.1]nona-2,6- diene framework found in biologically active molecules highlights the synthetic utility of this method. Copyright
Synthesis and evaluation of novel pyrazolidinone analogs of PGE2 as EP2 and EP4 receptors agonists
Zhao, Zhong,Araldi, Gian Luca,Xiao, Yufang,Reddy, Adulla P.,Liao, Yihua,Karra, Srinivasa,Brugger, Nadia,Fischer, David,Palmer, Elizabeth
, p. 6572 - 6575 (2008/09/16)
Replacement of the hydroxy cyclopentanone ring in PGE2 with chemically more stable heterocyclic rings and substitution of the unsaturated α-alkenyl chain with a metabolically more stable phenethyl chain led to the development of potent and selective analogs of PGE2. Compound 10f showed the highest potency and selectivity for EP4 the receptor.
