The diastereospecific formation of δ-hydroxyalkylbutenolide phosphonate has been achieved via a vinylogous Mukaiyama aldol reaction. The reaction was performed using α-ketophosphonate 1 and 2-(trimethylsilyloxy)furan 2 mediated by Cu(OTf)(2) and 2,2,2-trifluoroethanol as additive in CH(2)Cl(2). The reaction proceeds rapidly and affords the corresponding 5-(hydroxy(aryl)methyl) furan-2(5H)-one p...

Wild barley (Hordeum vulgare ssp. spontaneum) has strong grain dormancy, a trait that may enhance its survival in non-cultivated environments; by contrast, cultivated barley (Hordeum vulgare ssp. vulgare) has weaker dormancy, allowing uniform germination in cultivation. Malting barley cultivars have been bred for especially weak dormancy to optimize their use in malt production. Here, we analyz...

Dihydrobenzo[a]fluorene derivatives have been prepared by a formal intramolecular [3 + 3] cycloaddition of o-alkynylstyrenes bearing a secondary alkyl group at the β-position of the styrene moiety. The process, catalyzed by a cationic gold(I) complex, involves a 1,2-hydride migration as the key step. 6,11-Dihydro-5H-benzo[a]fluorenes could be obtained from the initially generated 6,6a-dihydro-5...

The molecules of 10-methyl-8-phenyl-11-(3-pyridyl)-6,8-dihydro-5H-benzo[f]pyrazolo[3,4-b]quinoline, C26H20N4, (I), are linked by a single C-H...N hydrogen bond into cyclic R(4)(4)(12) tetramers generated by a -4 axis. In isomeric 10-methyl-8-phenyl-11-(4-pyridyl)-6,8-dihydro-5H-benzo[f]pyrazolo[3,4-b]quinoline, (II), which crystallizes with Z' = 2 in space group P2(1)2(1)2, the two independent ...

A novel series of N-sulfonyl homoserine lactone derivatives 5a-l has been designed, synthesized and evaluated for quorum sensing inhibitory activities towards violacein production. Of the compounds synthesized, compound 5h was found to possess an excellent level of enantiopurity (99.2% e.e.). The results indicated that compounds bearing an ortho substituent on their phenyl ring exhibited excell...

Friedel-Craft acylation at 100 °C of 2,5,9,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzocycloheptene [ar-himachalene], a sesquiterpenic hydrocarbon obtained by catalytic dehydrogenation of α-, β- and γ-himachalenes, produces a mixture of two compounds: (3,5,5,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzocyclohepten-2-yl)-ethanone (2, in 69% yield), with a conserved reactant backbone, and 3, with a diff...

The diastereospecific formation of β-N-glycoside-linked α-amino-2(5H)-furanone has been achieved with high yield via a vinylogous Mannich reaction. The reaction was performed by using O-pivaloylated galactosylamine 1 as a chiral template and ZnCl(2)·Et(2)O as a promoter in Et(2)O. Imines 3 of aromatic compounds and trimethylsiloxyfuran 4 were converted to N-galactosyl α-amino-2(5H)-furanone 5, ...

The chemical structures of AT2433-A1 (2), AT2433-A2 (3), AT2433-B1 (4) and AT2433-B2 (5) were elucidated by degradation and spectroscopic studies. Compounds 2-5 are disaccharides closely related to rebeccamycin. The aglycone in 2 and 3 was determined to be 6-N-methyl-11-chloro-5H-indolo[2,3-a]pyrolo[3,4-c]carbazole and in 4 and 5 it was determined to be 6-N-methyl-5H-indolo[2,3-a]pyrolo[3,4-c]c...

Two series of N-(aryl)-1-(hydroxyalkyl)pyrrolidine-2-carboxamides (2a-2g and 3a-3g) and 1,4-disubstituted 1,2,3-triazoles (5a-5h and 8a-8h) were synthesized. All the compounds, containing a lipophilic tail and a polar headgroup, were evaluated as sphingosine kinase (SphK) inhibitors by assessing their ability to interfere with the acetylcholine (Ach) induced relaxation of aortic rings pre-contr...

(+)-Cyanobacterin, a photosynthesis inhibitor of freshwater cyanobacterium Schytonema hofmanni, was synthesized in 6 steps from a readily accessible chiral synthon 5R-5-(l-menthyloxy)-2(5H)furanone.