Synthesis of Isoponcimarin

P . R o d i g h i e r o , A . G u i o t t o * , P . M a n z i n i , a n d G . P a s t o r i n i Ist ituto di Chimica Farmaceutica dell 'Universita di Padova , Centro di Studio della Chimica del Farmaco e dei Prodott i Bio logicamente attivi del C N R , V ia Marzolo 5, 1-35100 Padova , I taly Z. Naturforsch. 34b , 1010-1014 (1979); received February 19, 1979 Isoponcimarin, Isomeranzin, Dihydrooroselone, Synthesis Synthesis o f isoponcimarin, 7 (3 ' -methy l -2 ' , 3 ' epoxy -but i l oxy ) -8 (3 " -methy l -2 " -oxo butyl ) coumarin, a natural coumarin isolated f rom Poncirus trifoliata L., was obtained starting f r o m acetyl osthenol. F r o m the intermediate 7 -acetoxy-8 (3 ' -methyl -2 ' -oxobuty l ) coumarin, the coumarin derivatives isomeranzin and dihydrooroselone were also prepared.