Total syntheses of the furanosesquiterpenes crassifolone and dihydrocrassifolone via an Au(i)-catalysed intramolecular Michael addition reaction†
Abstract
The racemic modifications of title natural products 1 and 2 have been synthesised for the first time. The key step was the Au(I)-catalysed conversion of the furanyl-substituted ynone 13 into the annulated furan 14.