Bio-derived furoic acids and their derivatives are unexpectedly reactive dienes in aqueous Diels–Alder cycloadditions with maleimides.

One of the most efficient methods (high yield, controlled stereochemistry, diverse functionality) to construct rings from smaller fragments is via cycloaddition reactions. The reverse reaction, namely splitting of a ring into smaller fragments is termed a cycloreversion reaction is also an important synthetic tool. (For example, in the present experiment it is the cracking of cyclopentadiene di...

Frankia sp. strain EI5c is a member of Frankia lineage III, which is able to reinfect plants of the Eleagnaceae, Rhamnaceae, Myricaceae, and Gymnostoma, as well as the genus Alnus Here, we report the 6.6-Mbp draft genome sequence of Frankia sp. strain EI5c with a G+C content of 72.14 % and 5,458 candidate protein-encoding genes.

The methanol extract of the bark of Ahus rubra showed antimicrobial activity against Gram-positive and Gramnegative bacteria. Diarylheptanoid and its glycoside (oregonin) were identijied as the two constituents responsible for this activity.

[reaction: see text] A high-yielding method is described for the rapid synthesis of very hindered cyclohexenes by the Diels-Alder reaction of hindered silyloxy dienes and dienophiles using the mixed Lewis acid catalyst system (AlBr(3)/AlMe(3)). Thus, reaction of the hindered diene 4 with various substituted enones gave good yields of the expected cycloadducts even though both partners are quite...

The enantioselective syntheses of the eunicellins ophirin B and astrogorgin have been completed. Ring-closing metatheses provide efficient access to the oxonene rings, and highly diastereoselective intramolecular Diels-Alder reactions resulted in the formation of the hydrobenzofuran portion of the molecules.