@article{dd2d938d96bc4277ab880d958e5c41f5,
title = "Structure and stereochemistry of the monobromotigogenins",
abstract = "Bromination of desoxytigogenin has been found to yield two isomeric 23-bromo-5α-25R-spirostans. The corresponding 3β-acetoxy-23-bromo-5α-25R-spirostans were also prepared from tigogenin actetate. A combination of physical methods based on mass spectrometry and NMR measurements, at 60- and 100-mc/s, have been used to confirm attack by bromine at C-23 of the spiroketal system. The configuration of each epimeric pair (at C-23, cf. III and IV) of isomers was also determined.",
author = "Kutney, {J. P.} and W. Cretney and Pettit, {G. R.} and Knight, {J. C.}",
note = "Funding Information: 1 Part XXIII of series, Sleroids and Related Natural Products. For the preceding contribution see, G. R. Pettit, D. S. Alkalay, P. Hofer and P. A. Whitehouse, Terraherlron 20, 1755 (1964). a Financial support for the investigations carried out at the University of British Columbia was provided by the National Research Council of Canada, while the University of Maine program was supported in part by PHS Research Grants CA-04074-04 to CA-U4074-06 from the National Cancer Institute, Public Health Service, a Inquiries may be addressed to this author. 4 Smith Kline and French Postdoctoral Fellow, 1962. 6 R. E. Marker and E. Rohrmann, J. Amer. Chem. Sot. 61,846 (1939). o R. E. Marker, D. L. Turner, A. C. Shabica and P. R. Ulshafer, J. Amer. Chem. Sot. 63,1032 (1941). {\textquoteright} C. Djerassi, H. Martinez and G. Rosenkranz, J. Org. Chem. 16,303 (1951). a Recommendations for the systematic naming of steroidal sapogenins have recently been prepared by G. P. Mueller and G. R. Pettit, Experientiu 18, 404 (1962). See also, G. R. Pettit, Ibid. 19, 124 (1963). In regard to the stereochemistry at C-25 a recent communication by E. O{\textquoteright}Donnell and M. F. C. Ladd, Chem. & Ind. 1984 (1963) is of interest. * G. P. Mueller and L. L. Norton, J. Amer. Chem. Sot. 76,749 (1954). 1999",
year = "1964",
doi = "10.1016/S0040-4020(01)98471-6",
language = "English (US)",
volume = "20",
pages = "1999--2006",
journal = "Tetrahedron",
issn = "0040-4020",
publisher = "Elsevier Limited",
number = "9",
}