¹³C NMR of coumarins. V—3‐prenylated coumarins

Abstract

Abstract 13 C NMR data of nineteen coumarins, twelve of which bear a prenyl (isoprenoid) side‐chain at C‐3, are reported and compared with those of the C‐3 unsubstituted compounds. Unlike the linear isomers, no γ‐effect is observed in the corresponding angular derivatives; this is proposed as spectroscopic criterion for distinguishing between these isomers.