We report a new synthetic route to 5,11-disubstituted indeno[1,2-b]fluorene-6,12-diones that is amenable to larger scale reactions, allowing for the preparation of gram amounts of material. With this new methodology, we explored the effects on crystal packing morphology for the indeno[1,2-b]fluorene-6,12-diones by varying the substituents on the silylethynyl groups.

The total synthesis of the potent microtubule-stabilizing, antimitotic agent (+)-discodermolide is described. The convergent synthetic strategy takes advantage of the diastereoselective alkylation of a ketone enolate to establish the key C15-C16 bond. The synthesis is amenable to preparation of gram-scale quantities of (+)-discodermolide and analogues.

Direct arylation reactions of nitrobenzenes and aryl halides occur in good yield and high ortho regioselectivity. These reactions can be performed on gram scale with as few as 3 equiv of the nitro arene relative to the aryl halide. The synthetic utility of this method is demonstrated via rapid synthesis of a Boscalid intermediate.

An improved protocol for the formal elimination of propene from organic substrates is reported. This process entails the ozonolytic conversion of an alkene to a methoxy hydroperoxide which undergoes fragmentation mediated by copper and iron. The use of soluble Cu(BF4)2 and Fe(BF4)2 results in reproducible results up to a 100 gram scale.

An efficient gram scale synthesis of 3-fluoro-1-hydroxyacetone phosphate (FHAP) has been developed. As a close analog to dihydroxyacetone phosphate, FHAP was used as a novel donor substrate for rabbit muscle aldolase catalyzed reactions. The different binding affinities of the gem-diol and keto form of FHAP were studied by (19)F-NMR.

An improved procedure for isolation of 5-amino-3-methyl-1,2,4-thiadiazole in pure form on a multi-gram scale without chromatography is reported. Its 1H and 13C-NMR and IR data are presented and previously published erroneous data corrected. The molecular structure is confirmed by X-ray diffraction which shows layers consisting of an elaborate two-dimensional hydrogen bonded network of molecules.

Oligosaccharidic moieties of GM(2) and GM(3) gangliosides bearing an allyl or a propargyl aglycon, are efficiently biosynthesized on the gram scale by growing metabolically engineered Escherichia coli cells in the presence of the corresponding lactoside acceptors and sialic acid.

background: the role of the hospital environment as a source of dissemination of pathogens is critical. environmental surfaces in the intensive care units (icus) are suitable for the growth of gram-negative bacteria that normally circulate between the environment and patients and can cause outbreaks of nosocomial infections. in this study, the prevalence of gram-negative bacilli in the environm...