The use of 5-hydroxymethylfurfural towards fine chemicals: Synthesis and direct arylation of 5-HMF-based oxazoles.

5-hydroxymethylfurfural (5-HMF) is a renewable platform chemical used as a source for obtaining diverse fine chemicals. In this letter, we report the synthesis of 5-HMF-based oxazole compounds. While 5-HMF could be easily converted to the oxazole derivative through the Van Leusen reaction, the direct arylation step needed to access the final compounds was problematic at first. After optimization, a palladium-catalyzed procedure has been developed and used for the synthesis of a series of thirty three derivatives. This article reports an extension of the late-stage CH arylation reaction as an application to the oxazole platform derived from biosourced 5-HMF. The challenges in the preparation of the derivatives containing some electron-withdrawing substituents were overcome by the use of a palladium-free method.

Halogenated and Nonhalogenated Metabolites from the Marine-Alga-Endophytic Fungus Trichoderma asperellum cf44-2

One new bisabolane sesquiterpene, bisabolan-1,10,11-triol (1), one new norbisabolane sesquiterpene, 12-nor-11-acetoxybisabolen-3,6,7-triol (2), two new naturally occurring monoterpenes, (7S)- and (7R)-1-hydroxy-3-p-menthen-9-oic acids (3 and 4), one new naturally occurring trichodenone, dechlorotrichodenone C (5), one new chlorine-containing trichodenone, 3-hydroxytrichodenone C (6), one new diketopiperazine, methylcordysinin A (7), and one new naturally occurring oxazole derivative, 4-oxazolepropanoic acid (8), were isolated from the culture of a marine brown alga-endophytic strain (cf44-2) of Trichoderma asperellum. Their structures and relative configurations were determined by extensive 1D/2D NMR and mass spectrometric data, and the absolute configurations of 3–6 were assigned by analysis of the ECD spectra aided by quantum chemical computations. Compounds 1, 2, 5, and 6 showed growth inhibition of some marine phytoplankton species and pathogenic bacteria.