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.
Chromane 衍
生物(I)##STR1##其中R.sup.1,R.sup.2和R.sup.3为H或C.sub.1-C.sub.8-烷基,R.sup.4为H,C.sub.1-C.sub.8-烷基或C.sub.1-C.sub.8-酰基,R.sup.5为C.sub.1-C.sub.8-烷基,通过将
氢醌(II)##STR2##与具有相同作用的Lewis酸或Lewis酸衍
生物以及nitrile CH.sub.2 .dbd.CH--C(R.sup.5)(OR.sup.6)CN(III)反应,其中R.sup.6为H,C.sub.1-C.sub.4-酰基或C.sub.1-C.sub.4-烷基,或与III形成的化合物在惰性溶剂存在下制备。