SYNTHESIS OF (+)-5-EPI-ARISTOLOCHENE AND (+)-1-DEOXYCAPSIDIOL FROM CAPSIDIOL

(+)-5-epi-Aristolochene, a common precursor of the phytoalexins capsidiol and debneyol, was synthesized from capsidiol (ex. Capsicum annum) via (+)-1-deoxycapsidiol. It is identical (TLC, GC, GC-MS, 1H NMR) with the enzymic product from cell-free preparations from elicitor-treated suspension cultures of Nicotiana tabacum incubated with either [1-14C]isopentenyl pyrophosphate or E,E-[1-3H]farnesyl pyrophosphate. The (+)-1-deoxycapsidiol was identical (GC, MS, 13C and 1H NMR) to a natural sample previously obtained from elicitor-treated fruits of C. annum. An isomer of 1-deoxycapsidiol, formed during the synthesis of this compound, was identified as 4-epi-eremophila-1(10),11-diene. © 1990.