Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Diels-Alder reaction of citral dienol acetate 3 with in-situ generated p-benzoquinones from 4 (ad) furnished cycloadducts 5 (ad) in quantitative yields. Brief exposure of 5b towards activated silica gel furnished acyl migrated product 6a in quantitative yield.