Synthesis of lupiwighteone via a para-Claisen-Cope rearrangement

The lanthanide catalysed para-Claisen-Cope rearrangement has been used as the key step in a short synthesis of the prenylated isoflavone, lupiwighteone. The Mitsunobu reaction was employed for the 5-O-prenylation of the acid/base sensitive acetylated isoflavone to afford the allyl aryl ether precursor, which was then rearranged under mild conditions in good yield. Rearrangement of the isoflavone gave the 8-prenylisoflavone as a single product, in good yield. (C) 2003 Elsevier Science Ltd. All rights reserved.