Efficient reduction of monoand disubstituted norbornyl α-diketones with zinc in [bmimBF4]:[H2O] to afford the corresponding acyloins in excellent yields and diastereoselectivities is described. In case of the monosubstituted norbornyl α-diketones, very high regioselectivities ranging from 90:10 to 100:0, in favor of diastereomer possessing endohydroxyl diagonal to endo-substituent were observed.

The composition of lipophilic extractives in the cortex and pith of elephant grass ( Pennisetum purpureum Schumach.) stems was thoroughly studied by gas chromatography-mass spectrometry. The predominant compounds were fatty acids followed by sterols (in free and conjugated forms as esters and glycosides). Other steroid compounds, as steroid hydrocarbons and ketones, were also present. Addition...

Oxidation of 2-hydroxy-9,10-dialkynylanthracenes resulted in highly regioselective dimerization to furnish metastable dearomatized 1,4-diketones rather than stable aromatic diols. The 1,4-diketones were converted to oxahelicenes, which exhibited strong fluorescence both in solution and solid state as well as chiroptical properties.

Thiazolium carbene-catalyzed reaction of aromatic 1,2-diketones with enones in aprotic solvents gave double acylation products in good yields, whereas hydroacylation products formed by Stetter reaction were not detected at all. These results suggested the generation of aroyloxyenamine species from the 1,2-diketones instead of hydroxyenamines (Breslow intermediates).