Efficient and regioselective synthesis of γ-lactone glycosides through a novel debenzylative cyclization reaction

Green synthesis, crystal structure, and antifungal activities of (E)-4-arylidene-5-oxotetrahydrofuran

A series of γ-lactone derivatives (E)-4-arylidene-5-oxotetrahydrofuran derivatives were synthesized via a tandem Passerini 3CC/SN cyclization microwave-assisted one-pot method efficiently starting from Baylis Hillman acids, aryl glyoxals and isocyanides, and using ionic liquid as reaction medium. The products were characterized by hydrogen nuclear magnetic resonance spectroscopy (1H-NMR), carbon nuclear magnetic resonance spectroscopy (13C-NMR). Single crystal X-ray analysis of the compound RPDFB clearly confirmed its assigned chemical structures. Meanwhile, the effects of four compounds (RPDFB, RPDFC, RPDFI, RPDFJ) on the growth inhibition activity of Gibberella zeae were detected, and found that the compound RPDFB has significant growth inhibition activity to Gibberella zeae.

Evolution of the Synthesis of Remdesivir. Classical Approaches and Most Recent Advances

The broad-spectrum antiviral Remdesivir, a monophosphate nucleoside analogue prodrug (ProTide), was repurposed. In May 2020, it received emergency approval by the FDA, being the first drug approved to fight the new coronavirus (COVID-19) disease which targets the virus directly. The main synthetic strategies toward Remdesivir, and their relevant modifications, are presented and discussed, to provide a panoramic view of the state-of-the-art and the more important advances in this field. Recent progress, proposed improvements, and uses of novel technologies for the synthetic sequence are also detailed.

Regioselective Synthesis of Difluorinated C-Furanosides Involving a Debenzylative Cycloetherification

A highly regioselective synthesis of valuable gem-difluorinated C-furanosides from unprotected aldoses via a debenzylative cycloetherification (DBCE) reaction induced by diethylaminosulfur trifluoride is descibed. The scope and limitations of this DBCE reaction are described using a series of commercially available pentoses and hexoses to afford, without selective protection/deprotection sequences, the corresponding gem-difluorinated C-furanosides in moderate to good yields.