An approach to the synthesis of pimpinellin
It has been over forty years since pimpinellin was isolated pure and its structure determined. We wished to explore possible routes for its total synthesis, unknown to this time. One route was via methyl 5-formyl-4,6,7-trimethoxycoumarilate. The route of Paul was reexamined through cleavage of 2,3,4,6-tetramethoxy-benzaldehyde to 2-hydroxy-3,4,6-trimethoxybenzaldehyde and its condensation to 4,6,7-trimethoxycoumarilic acid. Paul reported low yields and difficult purification steps. We were able to isolate the compounds pure but in too low yields to warrant further work at this time. Evidence suggests the synthesis of methyl 5-formyl-4,6,7-trimethoxycoumarilate, but lack of starting material and time prevented further examination now. An alternate route, via dihydrocinnamic acids followed by oxidation to quinones and reduction, would provide a needed phenolic group. We found that 2,3,4-trimethoxydihydrocinnamic acid and its ester did not form a quinone on oxidation, but ethyl 2,3,4,6-tetramethoxydihydrocinnamate did form a quinone on oxidation with chromic acid or argentic oxide.
College and Department
Chemistry and Biochemistry
BYU ScholarsArchive Citation
Wang, Paul Sun-Chi, "An approach to the synthesis of pimpinellin" (1975). Theses and Dissertations. 8377.