Synthesis and the mass and nuclear magnetic resonance spectra of side chain isomers of cholesta-5,22-dien-3灏?ol and cholesta-5,22,24-trien-3灏?ol was written by Hutchins, Roderick F. N.;Thompson, Malcolm J.;Svoboda, James A.. And the article was included in Steroids in 1970.Electric Literature of C23H26BrP This article mentions the following:
The previously unknown 22-cis-cholesta-5,22-dien-3灏?ol, 22-cis and 22-trans isomers of cholesta-5,22,24-trien-3灏?ol, 20-iso-22-trans-cholesta-5,22,24-trien-3灏?ol, 22,24-trans,-trans-26-homocholesta-5,22,24-trien-3灏?ol, and the known 22-trans-dehydrocholesterol were synthesized. Their IR, mass and NMR spectra are presented. These compounds undergo fragmentation processes that are governed primarily by the site of the unsaturation and not by their stereochemistry. However, the C-methyl resonances in the NMR spectra are influenced by their chem. environment. In the experiment, the researchers used many compounds, for example, Isopentyltriphenylphosphonium bromide (cas: 28322-40-9Electric Literature of C23H26BrP).
Isopentyltriphenylphosphonium bromide (cas: 28322-40-9) belongs to organobromine compounds. Bromo compounds are employed in a variety of metal-catalyzed coupling reactions. They are also ideal candidates for the synthesis of Grignard reagents that have wide-applicability in organic synthesis. alpha-Bromoesters are employed in the Reformatsky reaction for the synthesis of beta-hydroxyesters. Many of the alkyl bromine derivatives are excellent alkylating agents since bromides are good leaving groups. Tribromides, like tetrabutylammonium tribromide, are used as a solid source of bromine. N-bromosuccimide (NBS) is used for the selective bromination of allylic bonds.Electric Literature of C23H26BrP
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary