(-)-Isopodophyllotoxin has been synthesised by a route involving an as
ymmetric Diels Alder reaction between (5R)-menthyloxy-2(5H)-furanone a
nd an arylisobenzofuran. Raney nickel reduction of the major adduct af
fords 10-menthyloxyisopicropodophyllin which is converted into (-)-iso
podophyllotoxin.