Chromane derivatives (I) ##STR1## where R.sup.1, R.sup.2 and R.sup.3 are H or C.sub.1 -C.sub.8 -alkyl, R.sup.4 is H, C.sub.1 -C.sub.8 -alkyl or C.sub.1 -C.sub.8 -acyl and R.sup.5 is C.sub.1 -C.sub.8 -alkyl are prepared by reacting a hydroquinone (II) ##STR2## with a Lewis acid or a Lewis acid derivative having the same action, and with a nitrile CH.sub.2 .dbd.CH--C(R.sup.5)(OR.sup.6)CN (III), where R.sup.6 is H, C.sub.1 -C.sub.4 -acyl or C.sub.1 -C.sub.4 -alkyl, or with a compound from which III is formed in situ, in the presence of an inert solvent.