CHEMISTRY OF SAURURUS-CERNUUS .6. 3 NEW NEOLIGNANS

From the relatively more lipophilic fraction of the extract of Saururus cernuus, seven neolignans were isolated of which three, named (—)-saururin, (—)-saururenin, and (+)-saururinone, are new and belong to the l,4-diaryl-2,3-dimethylbutane group, with saururinone being a novel ketoneolignan. The remaining four were identified as (—)-austrobailignan 6, another member of the 1,4-diarylbutane group, and (—)-calopiptin, (—)-galbacin, and(+)-zuonin A, all three of which belong to the 2,5-diaryl-3,4-dimethyltetrahydrofuran group. Of these, zuonin A has the rarely seen stereochemistry for the tetrahydrofuran ring: 2/3 cis, 3/4 cis, and 4/5 trans. © 1990, American Chemical Society. All rights reserved.