Total synthesis of (±)-heliannuol D, an allelochemical from Helianthus annuus

The total synthesis of (+/-)-heliannuol D and its epimer has been completed in 9 steps and 12% overall yield from 2-methylanisole. The benzoxepane moiety of the title compound, a common structural feature in the heliannuol family of natural products, is prepared by a biomimetic opening of an epoxide by a phenol. (C) 2000 Elsevier Science Ltd. All rights reserved.