ENANTIOEXCESS MONOTERPENES FROM ROOTS OF ASIASARUM-SIEBOLDI

Three new monoterpenes, named (+)-asarinol C, (-)-asarinol C and (+)-a sarinol D have been isolated from the roots of Asiasarum sieboldi, alo ng with a known compound, ydroxy-l-methylethyl)-2-methyl-2-cyclohexen- 1-one. On the basis of spectral analyses including X-ray crystallograp hic analysis, the structures of (+)-asarinol C, (-)-asarinol C and (+) -asarinol D have been established as ,7,7-trimethyl-8-oxabicyclo[3,21] -hept-3-en-2-one, ,7,7-trimethyl-8-oxabicyclo[3.2.1]-hept-3-en-2-one a nd 4,5-dihydroxy-2,6,6-trimethyl-2-cyclohepten-1-one, respectively. Th e optical resolution of the above compounds suggested that these compo unds were enantioexcess monoterpenes.