Chemodivergent Reactions of Aromatic Ring-Annulated Hexahydrocyclopentafurans with Various Aldehydes.

Hexahydro-2-cyclopenta[]furan fused to electron-rich aromatic rings reacts with various aromatic aldehydes in different modes to build diverse frameworks. The reaction of a dimethoxybenzene-fused cyclopentafuran generated diquinanes fused with a hydrofuran ring, indenopyrans, or diarylindanes depending upon the type of aromatic aldehydes, whereas an indole-annulated cyclopentafuran generated another type of diquinane fused with hydrofuran ring or benzylidenecyclopentafuran. The chemodivergence is due to the different properties between indole- and dimethoxybenzene-fused hydrocyclopentafurans.

Monitoring the Dissolution Behavior of Novel Pharmaceutical Cocrystals Consisting of Antimalarial Drug Artemisinin with Probe-Type Low-Frequency Raman Spectrometer.

Artemisinin (ART) is a most promising antimalarial agent. However, its low aqueous solubility limits its oral absorption, resulting in low bioavailability. In this study, we have successfully discovered a novel cocrystal with 2-methyl resorcinol (ART-2MRE) providing improved solubility compared with a previously reported cocrystal with resorcinol (ART-RES).

Toward the stereochemical assignment of euvesperins A and B: total synthesis of the possible structures of the natural products.

The possible structures of euvesperins A and B were synthesized. The results of our synthesis suggest that euvesperin A may be a mixture of the (2,3,4,7) and (2,3,4,7) isomers and euvesperin B may be a mixture of the (2,3,4,7) and (2,3,4,7) isomers in consideration of their putative biosynthetic pathways.