title: C-24 Stereochemistry of Marine Sterols: (22E)-25,28-Dimethyl- stigmasta-5,22,28-trien-3β-ol and 25,28-Dimethylstigmasta-5,28-dien-3β-ol.
abstract: The C-24 configurations of (22E)-25,28-dimethylstigmasta-5,22,28-trien-3β-ol (1) and 25,28-dimethylstigmasta-5,28-dien-3β-ol (2), isolated from the sponge Topsentia ophiraphidites in our previous work, were determined to be both S, through the synthesis of stereodefined (24S)- and (24R)-epimers of 1 and 2 and comparison of the 1H and 13C NMR spectroscopic data. In addition, the C-24 configurations of the marine sterols having the same structures as 1 and 2 and their derivatives were also assigned for the first time by NMR comparison.
authors: Rie
authors: R
authors: Nojo
authors: Shizue
authors: S
authors: Echigo
authors: Noriyuki
authors: N
authors: Hara
authors: Yoshinori
authors: Y
authors: Fujimoto
mesh_terms: D000818:Animals; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011161:Porifera / Q000737:chemistry*; D013261:Sterols / Q000138:chemical synthesis / Q000737:chemistry*; D013265:Stigmasterol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: C000595942:25,28-dimethylstigmasta-5,22,28-trien-3beta-ol; C000595943:25,28-dimethylstigmasta-5,28-dien-3beta-ol; D013261:Sterols; D013265:Stigmasterol