2429-48-3Relevant academic research and scientific papers
4,5-Cyclopropanocholestan-3β-ol Substrates for Cholesterol Oxidase and Their 1H NMR Assignments
Sampson, Nicole S.,McCann, Amy E.
, p. 5893 - 5897 (1997)
We have assayed 4,5-cyclopropanocholestan-3-ols and 4,5-cyclopropanocholestan-3-ones and tested them as substrates and inhibitors of cholesterol oxidase. The 4,5-cyclopropanocholestan-3/3-ols (α and β) are substrates of cholesterol oxidase that are converted to their respective ketones 1000-fold more slowly than cholesterol. The induced ring-current effects of a cyclopropane ring are clearly illustrated in the 1H NMR spectra of these sterols. These shielding effects are dramatic because of the rigidity of the steroid backbone. Assignments of the 1H resonances of the A, B, and cyclopropyl rings of the sterols have been made using DQF-COSY and NOESY experiments. We have assigned the upfield multiplet at approximately 0.5 ppm to H6α in both isomers. H6α is shielded by the cyclopropyl σ bond. H6β is deshielded by the cyclopropane ring and appears at approximately 2.0 ppm in both isomers.
THE BROMINATION OF THE EPIMERIC 4,5-CYCLOPROPANOCHOLESTAN-3-ONES
Fajkos, Jan,Joska, Jiri,Zajicek, Jaroslav
, p. 3455 - 3473 (2007/10/02)
Bromination of the epimeric 4,5-cyclopropanocholestan-3-ones I and XIII has been studied and structures of the products were established by chemical and spectral means.Confirmation of the A ring in the bromo ketones and bromohydrins is discussed on the basis of spectral evidence.
SIMMONS-SMITH METHYLENATION OF THE 4,5-DOUBLE BOND IN 19-HYDROXYLATED STEROIDS
Joska, Jiri,Fajkos, Jan
, p. 1850 - 1859 (2007/10/02)
Simmons-Smith methylenation of 4-cholestene-3α,19-diol 19-monoacetate and of 4-cholestene-3β,19-diol 19-monoacetate has been studied and structure of the products established by spectral means.
