An asymmetric total synthesis of ent-sandaracopimaradiene, a biosynthetic intermediate of oryzalexins, via B-alkyl Suzuki-Miyaura coupling and Lewis acid-mediated B-ring formation as key steps was achieved.

Condensation of an aldehyde with an α-amino-ester, followed by a tandem process involving cyclization to a seven-membered ring, deprotonation to an intermediate azomethine ylide and intramolecular dipolar cycloaddition gave tricyclic products related to stenine and neostenine.

There have been few investigations of the cause of nuclear invagination and lobule formation. The human pancreatic cancer cells MIA PaCa-2 often show nuclear lobulation and well-developed juxtanuclear aggregates of intermediate filaments with thick bundles of intermediate filaments developed from them. Therefore MIA PaCa-2 cells were used as model cells to examine whether or not there is any re...

A heterogeneous catalyst for producing epoxidized vegetable oils, an important intermediate in the production of non-isocyanate polyurethanes, is essential product separation and decreasing side-reaction, i.e., ring-opening reaction, via Prileschajew method. The development reliable kinetic models considering key variables both phases mass transfer phenomena missing literature. reaction pathway...

Platinum dichloride-catalyzed hydroxy- or alkoxycyclization of cyclohexadienynes gives indenol derivatives, whereas hydroxy- or alkoxycyclization of cycloheptadienynes produces azulenol derivatives. The cyclization reaction proceeds via a cyclopropyl platinacarbene intermediate and allows for the direct stereocontrol of three contiguous stereogenic centers of the fused bicyclic skeletons. The t...

A convergent synthesis of the C31-C52 bis-tetrahydropyran core of the natural product amphidinol 3 is reported. A common intermediate was synthesized from d-tartaric acid utilizing an asymmetric glycolate alkylation/ring-closing metathesis sequence to construct the THP rings. Differential elaboration of the common intermediate allowed the synthesis of two distinct coupling partners which were j...

Asymmetric allylation of (hetero)aromatic aldehydes by a zinc(II)-allylbutyrolactone species catalyzed by a chiral BINOL-type phosphoric acid gave β-substituted α-methylenebutyrolactones in 68 to >99% ee and 52-91% isolated yield. DFT studies on the intermediate Zn2+-complex - crucial for chiral induction - suggest a six-membered ring intermediate, which allows the phosphoric acid moiety to act...

PURPOSE Based on latest analyses disclosing an inverse association between ring-like structures in macular pigment (MP) spatial profile and age-related macular degeneration, we performed additional analyses of MP measurements obtained in participants of our earlier lutein nutrition effects measured by autoflourescence (LUNA) study to disclose if oral lutein (L) and zeaxanthin (Z) can attenuate,...

A series of chalcones substituted by a quinoxaline unit at the B-ring were synthesized and tested as inhibitors of breast cancer resistance protein-mediated mitoxantrone efflux. These compounds appeared more efficient than analogs containing other B-ring substituents such as 2-naphthyl or 3,4-methylenedioxyphenyl while an intermediate inhibitory activity was obtained with a 1-naphthyl group. In...