A new intramolecular recyclization in water-base cleavage reaction of 2,2-dialkyl-4-hydroxymethylbenz[f]iso indolinium bromides and chlorides

The water‐base cleavage reaction of 2,2‐dialkyl‐4‐hydroxymethylbenz[f]isoindolinium bromides and chlorides (2b‐g) and (4a‐g) was investigated. It was established that the above‐mentioned salts in water‐base cleavage reaction undergo intramolecular recyclization. As a result 1,3‐dihydro‐4‐dialkylaminomethyl‐naphto[1,2‐c]furans (5a‐g) are obtained in 62‐72% yields. The same products in 65‐70% yields may be obtained by step cyclization cleavage reaction of dialkyl‐4‐hydroxybutyn‐2‐yl‐(3‐phenylpropargyl) ammonium salts (1b‐g) and (3a‐g), as well. The structure of the resulting amines 5a‐g are determined and approved by X‐ray diffraction, nmr and ir spectroscopic methods.