Catechol Cation exchange resin

Chromanols are prepared in good yields by cyclization of hydroquinone, resorcinol, and catechol with phytyl chloride in the presence of cation-exchange resin complexes of metal ions. ° The reaction of dihydrocoumarins with readily available 0 ,Grignard reagents has led to chromans which are spiro-substituted at the 2-position (125). The initially formed O-hydroxyphenylethyl cycloalkanols (124) were converted to chromans in high yield by simple acid treatment. ... 

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