FIELD OF THE INVENTION
The present invention relates to "DDQ mediated one step dimerisation of dihydro product of toxic .beta.-asarone rich Acorus calamus oil towards formation of novel neolignan: 3-ethyl-2-methyl-3-(2",4",5"-trimethoxy)phenyl-1-(2',4',5"-trimethoxy) phenyl-1-propene" in which