@article{6b0c726244ef4687924662a387b8090d,
title = "Isobufadienolides",
author = "Knight, {J. C.} and George Pettit and Herald, {C. L.}",
note = "Funding Information: CHEMICAL COMMUNICATIONS, 1967 445 Isobufadienolidest By J. C. KNIGHT, G. R. PETTIT,* and C . L. HERALD (Department of Chemistry, Arizona State University, Tempe, Arizona 85281) A COMMON structural feature of certain physio- Several 2-pyrones have been prepared in which logically active steroids is an unsaturated the lactone ring is part4 of, or fusedb to, a steroid &lactone ring, which may be the 8-pyrone system nucleus, and conversion of the eburicoic acid side- typical of bufadienolides (I), or a dihydro-2- chain into a 2-pyrone group has been described.6 pyrone ring as in the anti-tumour agent withaferin Although routes to the 5'-substituted 2-pyrones A2 and related compounds.3 (I) and (11) have been reported,',* the natural This investigation was supported by Public Health Service Research Grants from the National Cancer Institute and in part by a grant from CIBA, Summit, New Jersey. ",
year = "1967",
doi = "10.1039/C19670000445",
language = "English (US)",
pages = "445--446",
journal = "Chemical Communications (London)",
issn = "0009-241X",
number = "9",
}