Process for the preparation of chroman derivatives

Abstract From the Canadian patent

Chroman derivatives of the general formula: ( C), in which R1 is hydrogen or C1-4-alkyl; R2 is C1-6-alkyl C3-6-cycloalkyl, optionally substituted aryl or optionally substituted aryl-C1-6-alkyl; R3, R5 and R6 independently of one another are hydrogen, halogen, C1-4-alkyl or optionally substituted aryl; and R4 is C1-6-alkyl C3-6-cycloalkyl, (C1-6-alkoxy)methyl, optionally substituted aryl optionally substituted aryl-C1-6-alkyl C1-6-alkanoyl or, optionally substituted aroyl are obtained from, hydroquinone derivatives and alkenes in the presence of Lewis acids. The chroman derivatives (I) are intermediates in the synthesis of pharmaceutically active substances, for example hypolipidemics.