1. C-24 Stereochemistry of Marine Sterols: (22E)-24-(Isopropenyl)-22-dehydrocholesterol and 24-Isopropenylcholesterol
- Author
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Yoshinori Fujimoto, Carmenza Duque, Noriyuki Hara, Gladys Jeanette Carderon, and Shizue Echigo
- Subjects
Magnetic Resonance Spectroscopy ,Stereochemistry ,Chemistry ,Molecular Conformation ,Stereoisomerism ,Colombian Caribbean sponge ,General Chemistry ,General Medicine ,Reference Standards ,Sensitivity and Specificity ,Nmr data ,Porifera ,Sterols ,Dehydrocholesterols ,Species Specificity ,24-isopropenyl-22-dehydrocholesterol ,Drug Discovery ,Topsentia ophiraphidites ,Animals ,Organic chemistry ,24-isopropenylcholesterol - Abstract
The C-24 configuration of (22E,24xi)-24-isopropenyl-22-dehydrocholesterol (1), which was recently isolated from the Colombian Caribbean sponge, Topsentia ophiraphidites, was investigated. Synthesis of the stereodefined (24R)- and (24S)-(22E)-24-isopropenyl-22-dehydrocholesterols (1a, 1b) followed by (1)H- and (13)C-NMR data comparison of these sterols established the (24R)-configuration of 1. In addition, (24R)- and (24S)-24-isopropenylcholesterols (2a and 2b) were also synthesized and their NMR data are provided. The C-24 configurations of the samples of 24-isopropenylcholesterol reported previously are discussed.
- Published
- 2006