Spirooliganone A (Morita), Microansamycin H (Sittihan), Gymnothelignan N (Lee),
3(11)-Epoxyhypoestenone (Wang/Chen)
Ophiofuranone A (3) was isolated from the endolichenic fungus Ophiospaerella
korrae. Rainer Schobert of the University Bayreuth prepared the
3-furanone
of 3 by the cyclization of the β-keto ester 1 to 2
(J. Org. Chem. 2022, 87, 6520.
DOI: 10.1021/acs.joc.2c00521).
Galanthamine (6), isolated from the Caucasian snow drop Galanthus caucasicus,
is used clinically for the treatment of the early stages of Alzheimer’s disease.
Richard C. D. Brown of the University of Southampton established the central
dihydrobenzofuran of 6 by the intramolecular
Heck cyclization of the cyclohexenyl ether 4 to 5
(J. Org. 1215071-12-7 web Mal-PEG3-NHS ester site Chem. 2022, 87, 1325.
DOI: 10.1021/acs.joc.1c02638). PMID:24182988
Spirooliganone A (10), isolated from Illicium oligandrum, an anise of
Southwest China, showed potent anti-viral activity. Masao Morita of ITSUU
Laboratory constructed the pentacyclic cyclohexadienone 9, having nearly the
full carbon skeleton of 10, by the hetero
Diels-Alder combination of the enone
7 with commercial sabinene 8
(Synlett 2022, 33, 581.
DOI: 10.1055/s-0040-1719904).
Microansamycin H (13) was isolated from the overexpression of the
transcriptional regulator gene mas13 in the bacterium Micromonospora sp.
En route to 13, Satapanawat Sittihan of the Chulabhorn Graduate Institute
optimized the selective anti-Baldwin intramolecular opening of the
Sharpless-derived epoxide 11, leading to the benzooxepane 12
(Org. Lett. 2022, 24, 4470.
DOI: 10.1021/acs.orglett.2c01760).
Gymnothelignan N (17) was isolated from the rainbow plant Gymnotheca
chinensis Decne, a widely used perennial Chinese herb. Kiyoun Lee of the
Catholic University of Korea assembled the tetrahydrofuran ring of 16 by the
addition of the aryl lithium 15 to the lactone 14, followed by
diastereoselective reduction
(J. Org. Chem. 2022, 87, 4316.
DOI: 10.1021/acs.joc.1c03167).
3(11)-Epoxyhypoestenone (20), isolated from Hypoestes forsskaolii, a shrub of
Arabia and tropical Africa that is extremely toxic to all livestock, showed
strong Hsp90 binding affinity. Liang Wang and Yue Chen of Nankai University
devised the tandem base-mediated epoxide opening-transannular oxa-Michael that
transformed the enone 18 into the bridged ether 19
(Angew. Chem. Int. Ed. 2022, 61, e202117476.
DOI: 10.1002/anie.202117476).
