Zimmerman, Mary P. et al. published their research in Journal of the American Chemical Society in 1984 | CAS: 28322-40-9

Isopentyltriphenylphosphonium bromide (cas: 28322-40-9) belongs to organobromine compounds. Many of the organo bromine compounds are relatively nonpolar. Bromine is more electronegative than carbon (2.8 vs 2.5) and hence the carbon in a carbon–bromine bond is electrophilic in nature. 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.Name: Isopentyltriphenylphosphonium bromide

Stereochemical effects in cyclopropane ring openings: biomimetic ring openings of all isomers of 22,23-methylenecholesterol acetate was written by Zimmerman, Mary P.;Li, Hui Ting;Duax, William L.;Weeks, Charles M.;Djerassi, Carl. And the article was included in Journal of the American Chemical Society in 1984.Name: Isopentyltriphenylphosphonium bromide This article mentions the following:

By using the unique stereochem. of the side chain in cholesterol, the dynamic influence of proximate chiral centers on the acid-promoted isomerizations of cyclopropanes is defined. Unexpectedly, when the cyclopropane is placed in the 22,23 position, either a backbone rearrangement is induced or unanticipated side-chain olefins arise, each dependent on the stereochem. of the cyclopropane starting material. The synthesis and stereochem. assignments of the 4 possible 22,23-methylenecholesterol acetates I are reported as well as the effect of stereochem. on the acid-promoted isomerization of these compounds [22R,23R]-I and [22S,23S]-I under the conditions of ring opening yield unexpected backbone rearrangement products, i.e., acetoxydimethylnorcholestadienes II, which can also be obtained from rearrangements of methylcholestadienol acetates III and IV. The stereochem. criteria governing the course of these isomerizations are discussed. In the experiment, the researchers used many compounds, for example, Isopentyltriphenylphosphonium bromide (cas: 28322-40-9Name: Isopentyltriphenylphosphonium bromide).

Isopentyltriphenylphosphonium bromide (cas: 28322-40-9) belongs to organobromine compounds. Many of the organo bromine compounds are relatively nonpolar. Bromine is more electronegative than carbon (2.8 vs 2.5) and hence the carbon in a carbon–bromine bond is electrophilic in nature. 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.Name: Isopentyltriphenylphosphonium bromide

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary