Polyene cyclization promoted by the cross-conjugated alpha-carbalkoxy enone system. Observation on a putative 1,5-hydride/1,3-alkyl shift under Lewis acid catalysis.

Polyene cyclization of compounds 3 and 4 under catalysis with AlCl3 and/or SnCl4 gave rise to complex bicyclic products 8 and 9, structures of which were highly unexpected, and X-ray analyses were invoked for unambiguously structural identification. Mechanistically, a tandem sigma-bond rearrangement process, including an unusual through-space 1,5-hydride or 1,3-alkyl shift as a key operation, is proposed.

A convenient new procedure for converting primary amides into nitriles.

An operationally simple and high-yielding procedure has been developed for the conversion of primary amides to the corresponding nitriles, using ethyl dichlorophosphate/DBU as the mild dehydrating agent.

Synthesis, crystal structure, structure-activity relationships, and antiviral activity of a potent SARS coronavirus 3CL protease inhibitor.

A potent SARS coronavirus (CoV) 3CL protease inhibitor (TG-0205221, Ki = 53 nM) has been developed. TG-0205221 showed remarkable activity against SARS CoV and human coronavirus (HCoV) 229E replications by reducing the viral titer by 4.7 log (at 5 microM) for SARS CoV and 5.

Diels-Alder chemistry of 2-diethoxyphosphinylcyclohex-2-enones. A new approach to complex phosphonates and synthetic applications of the beta-keto phosphonate system.

Enone phosphonates 1 and 2 were found to be excellent dienophiles for the Diels-Alder reaction, giving phosphonate-containing polycycles, and the phosphonate group of the resulting adducts facilitated both the installation of an angular alkyl group via a reductive alkylation process and the regioselective generation of a ring junction double bond via an intramolecular Wadsworth-Horner-Emmons reaction.