ChemInform Abstract: REAKTIONEN ′SEMICYCLISCHER′ 1,5‐DIKETONE MIT SCHWEFELWASSERSTOFF UND BORTRIFLUORIDAETHERAT

Reaction of 4-R-2-phenyltetrahydrobenzo[b]pyrylium and 9-R-sym-octahydroxanthylium salts with furfural and related compounds

“…It is known [1-3] that derivatives of cycloalka[b]chalcogenopyrylium salts are used as dyes in passive switches of optical quantum generators OQG [3], are used in photocompositions without silver salts [4], and exhibit biological activity [2]. Earlier we demonstrated that cycloalka[b]chalcogenopyrylium salts containing a γ-methyl group in the heterocycle and an α-methylene group in the alicycle react with aromatic aldehydes under harsh conditions at 100°C in a 1:3 mixture of acetic acid and acetic anhydride and form quantitative yields of the corresponding arylidene derivatives [1].…”