SYNTHETIC ROUTE TO AN AROMATIC ANALOG OF STRIGOL

An aromatic analogue which contains all but one of the carbon atoms of the witchweed seed germination stimulant strigol has been prepared. 6-Methyldihydrocoumarin was converted to a phenolic indanone (4) which was alkylated by reaction of its dianion with lithium bromoacetate. Reduction and acid treatment yielded a lactone (7) which (as its tert- butyldimethylsily 1 derivative) was converted to the hydroxymethylene compound 9. The sodium salt of 9 underwent O-alkylation with bromolactone 10 to yield the protected strigol and epistrigol analogues 11. Removal of the silyl ether was effected with aqueous fluoride at pH 5. © 1979, American Chemical Society. All rights reserved.