A practical way to synthesize chiral fluoro-containing polyhydro-2H-chromenes from monoterpenoids.

Conditions enabling the single-step preparative synthesis of chiral 4-fluoropolyhydro-2H-chromenes in good yields through a reaction between monoterpenoid alcohols with para-menthane skeleton and aldehydes were developed for the first time. The BF3·Et2O/H2O system is used both as a catalyst and as a fluorine source. The reaction can involve aliphatic aldehydes as well as aromatic aldehydes containing various acceptor and donor substituents. 4-Hydroxyhexahydro-2H-chromenes were demonstrated to be capable of converting to 4-fluorohexahydro-2H-chromenes under the developed conditions, the reaction occurs with inversion of configuration.

The short way to chiral compounds with hexahydrofluoreno[9,1-bc]furan framework: synthesis and cytotoxic activity.

A simple and efficient method for synthesizing chiral heterocyclic compounds with the hexahydrofluoreno[9,1-bc]furan framework via interaction between trans-4-hydroxymethyl-2-carene and aromatic aldehydes containing methoxy and hydroxyl moieties in the presence of montmorillonite clay was found. One of the synthesized compounds exhibited a high cytotoxic activity against lymphoblastoid cell line MT-4 (CTD50 0.9µM), which was higher than that of the comparative drug Doxorubicin. Death of cancer cells in this case substantially occurs via induction of apoptosis.