Tandem conjugate addition by an O-silylcyanohydrin derived carbanion to 5-(1-menthyloxy)-2(5H)-furanone, followed by reaction with an aromatic aldehyde gives two diastereoisomeric adducts. These afford a single product on treatment with tetrabutylammonium fluoride. Reduction with concomitant removal of the menthyloxy group, followed by acid catalysed cyclisation gave a homochiral tetrahydronaphthalene retrolactone which is an interesting structural isomer of podophyllotoxin.