Moon Ho Chang

Synthesis of novel 2,6-disubstituted-3,4-dimethylidene tetrahydropyrans via Prins-type cyclizationElectronic Supplementary Information (ESI) available: Experimental section. See http://www.rsc.org/suppdata/cc/b3/b307320c/

Synthesis of novel substituted tetrahydropyrans with adjacent exo-methylene groups at the C3 and C4 positions via Prins-type cyclization has been described.

Intermolecular Double Prins‐Type Cyclization: A Facile and Efficient Synthesis of 1,6‐Dioxecanes

Double or nothing: The title reaction converts a range of aromatic aldehydes and allenylmethyl/allyl silanes into 1,6-dioxecane derivatives in good to excellent yields (see scheme; Ar = aryl, Tf = triflate, THF = tetrahydrofuran, TMS = trimethylsilyl). In addition, the bisdiene product has been transformed into the corresponding tricyclic compound through a Diels-Alder reaction.

Indium-mediated consecutive 1,2-shift reaction and regioselective allylation of vinyl epoxides

Abstract Allyl indium, prepared from allyl bromide and indium metal in aprotic solvent, reacts with terminal vinyl epoxides at room temperature to afford various bishomoallyl alcohols in moderate to high yields via consecutive 1,2-shift reaction and regioselective allylation.

Intramolecular [3+2] nitrone-alkyne cycloaddition

Abstract It is demonstrated that the [3+2] cycloaddition of a nitrone to an alkyne is facile when the lengh of the tether connecting the two reacting sites is appropriate. The resulting [3+2] cycloaddition products, isoxazolidines can be further converted to 3-hydroxy-3-pyrrolin-2-ones and α-keto-β,γ-unsaturated esters by reductive and oxidative cleavage, respectively.

Synthesis and in vitro activity of new methylenepiperidinyl and methylenepyrrolidinyl oxazolidinone antibacterial agents.

We have prepared and evaluated the antibacterial activities of a series of substituted methylenepiperidinyl and methylenepyrrolidinyl oxazolidinones against several gram-positive strains including the resistant strains of Staphyloccus and Enterococcus, such as MRSA, CRSA, MSSA and VRE. Some of them showed comparable or superior in vitro activities (MIC) to vancomycin.

Synthesis of 3-Alkylidenecepham-4-carboxylic Acid derivatives by Samarium(II) Iodide Reduction

Abstract Samarium(II) iodide promoted reductive deacetoxylation of 7-aminocephalosporanic acid derivatives to synthesize 3-alkylidenecepham-4-carboxylates, which could be valuable intermediates for the synthesis of new cephalosporin antibiotics, was investigated.

Synthesis and Evaluation of 2β-0xyimino and Alkenylpenicillanic Acid Sulfone Derivatives as β-Lactamase Inhibitors

The synthesis and in vitro synergies of 2β‐alkenyl and oxyiminopenam sulfone derivatives are described. Most of the compounds synthesized exhibited good inhibitory activities and synergistic antibacterial activities with piperacillin and ceftriaxone, respectively, against several β‐lactamase producing strains. Particularly the 2β‐alkenylpenam sulfone derivatives, 1e and 1g, showed good synergistic activity with ceftriaxone against Citrobacter freundi NIH 10018‐68 and Proteus vulgaris 20. Also the compounds 2a, 2c, and 2f, 2β‐oxyiminopenam sulfone derivatives, exhibited improved synergistic activity with piperacillin against Citrobacter freundi NIH 10018‐68.