Reaction of 2a,8b-Dihydrobenzo[b]cyclobute[d]pyran-3-ones with Dimethylsulfoxonium Methylide.

Using dimethylsulfoxonium methylide as the methylene transfer reagent, 2a,8b-dihydrobenzo[b]cyclobute[d]pyran-3-ones were converted into 2,2'-biphenol derivatives as major products and dihydrodibenzofurans as minor products. The reaction mechanism was extrapolated from a deuteration experiment with CD2=S(O)(CD3)2.

Novel skeleton transformation reaction of α-pyrone derivatives to spirobicyclo[3.1.0]hexane derivatives using dimethylsulfoxonium methylide.

By applying a skeleton transformation reaction using dimethylsulfoxonium methylide, a novel reaction was identified by which 5,6,7,8-tetrahydrocoumarin with the electron-withdrawing group at C3 was led to the spirobicyclo[3.1.0]hexane-cyclohexane derivative.

Structure-based design of highly selective β-secretase inhibitors: synthesis, biological evaluation, and protein-ligand X-ray crystal structure.

The structure-based design, synthesis, and X-ray structure of protein-ligand complexes of exceptionally potent and selective β-secretase inhibitors are described. The inhibitors are designed specifically to interact with S(1)' active site residues to provide selectivity over memapsin 1 and cathepsin D. Inhibitor 5 has exhibited exceedingly potent inhibitory activity (K(i) = 17 pM) and high selectivity over BACE 2 (>7000-fold) and cathepsin D (>250000-fold).

Asymmetric total synthesis of (-)-Linderol A.

The first asymmetric total synthesis of (-)-Linderol A, a potent inhibitor of melanin biosynthesis of cultured B-16 melanoma cells, has been achieved via two key reactions: a diastereoselective [2+2] photocycloaddition of a coumarin-3-carboxylate bearing a chiral auxiliary with 3-methyl-1-butene and a subsequent stereoconvergent transformation of the photoadducts with use of dimethylsulfoxonium methylide to afford a tetrahydrodibenzofuran derivative.