Asymmetric Synthesis of γ-Hydroxy α-Enones by 1,8-Diazabicyclo[5.4.0]undec-7-ene-Catalyzed Stereoselective Rearrangement of Chiral α-Sulfinyl Enones

Diarylpentanones from the root of Wikstroemia indica and their cytotoxic activity against human lung A549 cells

One new diarylpentanone, 4(S)-hydroxy-1, 5-diphenyl -2(E)-en-1-pentanone (1), two diarylpentanones isolated from Wikstroemia indica for the first time (3 and 5) and two other known diarylpentanones were isolated from petroleum ether fraction of root of Wikstroemia indica. The structure of the new compound including absolute configuration was elucidated by extensive spectroscopic techniques, including 1D, 2D NMR, HR-ESI-MS and ECD spectroscopy. All isolated compounds were tested for their cytotoxic activity against cancer-derived cell lines A549. Compound 5 exhibited remarkable cytotoxic activity comparable to that of positive control cisplatin.

Sulfinyl-Mediated Stereoselective Functionalization of Acyclic Conjugated Dienes

The chemo- and stereocontrolled functionalization of conjugated sulfinyl dienes in a cascade process that involves a conjugate addition, diastereoselective protonation and a [2,3]-sigmatropic rearrangement is reported. Enantioenriched 1,4-diol and 1,4-aminoalcohol derivatives are obtained in a very straightforward manner. Further functionalization of these structures, including highly stereoselective epoxidation, dihydroxylation and the stereodivergent synthesis of several polyols in a controlled fashion is described.

An Asymmetric Redox Arylation: Chirality Transfer from Sulfur to Carbon through a Sulfonium [3,3]-Sigmatropic Rearrangement

A general, asymmetric redox arylation of ynamides and thioalkynes with chiral sulfoxides is reported. This is the first example of a general 1,4-chirality transfer from sulfur to a carbon stereocenter through a sulfonium [3,3]-sigmatropic rearrangement. This reaction delivers α-arylated thioesters and amides under mild conditions in an atom-economical manner. The products are formed in high yields with enantiomeric ratios up to 99.5:0.5. Quantum chemical calculations suggest a mechanism for the chirality transfer from sulfur to carbon and explain the experimentally observed correlation of the enantioselectivity with both the catalyst and the substrate.

Anti-inflammatory effects of alpinone 3-acetate from Alpinia japonica seeds

We aimed to investigate the bioactive components of Alpinia japonica as anti-inflammatory compounds using searches of the Alpinia genus, and subsequently demonstrated that alpinone 3-acetate markedly inhibits 12-O-tetradecanoyiphorbol 13-acetate-induced inflammation in a mouse model of ear edema. To assess other bioactivities of alpinone 3-acetate, we performed translatome analyses and compared them with those of hydrocortisone. Polysome-associated mRNAs were prepared from alpinone 3-acetate- or hydrocortisone-treated and control cells from 12-O-tetradecanoyiphorbol 13-acetate-induced THP-1-derived macrophages cultured in the presence of Escherichia coli O-111 lipopolysaccharide. Subsequent microarray analysis revealed that alpinone 3-acetate and hydrocortisone upregulated and downregulated the same 155 and 41 genes, respectively. Moreover, direct comparisons of translationally regulated genes indicated 5 and 10 gene probes that were upregulated and downregulated by alpinone 3-acetate and hydrocortisone, respectively. In conclusion, assays of 12-O-tetradecanoyiphorbol 13-acetate-induced inflammation ear edema in mice and polysome profiling of alpinone 3-acetate bioactivities indicated similar medicinal possibilities to those of hydrocortisone.

Remote stereocontrol in the synthesis of acyclic 1,4-diols and 1,4-aminoalcohols from 2-sulfinyl dienes

The highly diastereoselective conjugate addition of alcohols and amines (RXH) to enantiopure 2-sulfinyl dienes renders transient allylic sulfoxides which undergo sulfoxide-sulfenate rearrangement and sulfenate cleavage providing 2-ene-1,4-diols and 2-ene-1,4-aminoalcohols with up to 99:1 dr. The method allows for the generation of two stereocenters in a single synthetic operation with remote chirality transfer of one center into the other.

Enantiopure 1,4-diols and 1,4-aminoalcohols via stereoselective acyclic sulfoxide-sulfenate rearrangement

Treatment of acyclic α-hydroxy and α-tosylamino sulfinyl dienes with amines affords enantiopure 1,4-diol or 1,4-hydroxysulfonamide derivatives in good yields and diastereoselectivities. This one-pot procedure entails a conjugate addition that triggers a diastereoselective sulfoxide-sulfenate [2,3]-sigmatropic rearrangement.