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. ... The (±)- -chromanochromanones (2) and (3), representing the basic ring system of the natural insecticide rotenone, have been synthesised by a general procedure; the key step is 4-aroylation of the 4-phenyl-sulphonyl) chromans (7; Z=SO 2 Ph). ... A new approach is reported to ...