The cyperone route to agarofurans: stereoselective introduction of an hydroxy group at C-4

In this paper. the construction of the agarofuran tricyclic ring system bearing an hydroxy group at C-4. with the correct configuration at C-4, is described through the rearrangement of the 4.4a alpha-epox 9-benzoyloxy cyperone derivative 11. readily available from cyperone derivative 5c, under acidic conditions. (C) 2002 Elsevier Science Ltd. All rights reserved.