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 cont...

An efficient base catalysed approach to the synthesis of thiochromans/chromenes from allenylphosphonates (and an allenoate) and substrates having SH/OH and CHO groups at appropriate positions has been developed. Several azo-linked chromenes that are bright red pigments are also synthesized. This methodology involves the domino reactions of Michael addition and subsequent cyclisation by intramol...

A four-step synthesis of allylic trichloroacetimidates bearing a 2-proparyloxyaryl group has been developed from readily available 2-hydroxybenzaldehydes, and these have been used for the preparation of allylic amide derived 2H-chromenes using an Overman rearrangement and a 6-endo-dig hydroarylation. High yields of the 2H-chromenes were achieved using a stepwise approach involving an Overman re...

Catalytic activity of AlHMS was investigated as a cheap heterogeneous reusable catalyst in some multi-component reactions for the synthesis of various chromenes. Three-component reaction of 2-hydroxy-naphtoquinone with an aromatic aldehyde and dimedone or barbituric acid in H2O under reflux conditions was performed using AlHMS in relatively good yields. The approach was more extended using psue...

Catalytic activity of AlHMS was investigated as a cheap heterogeneous reusable catalyst in some multi-component reactions for the synthesis of various chromenes. Three-component reaction of 2-hydroxy-naphtoquinone with an aromatic aldehyde and dimedone or barbituric acid in H2O under reflux conditions was performed using AlHMS in relatively good yields. The approach was more extended using psue...