Etemad Moghadam, Guita published the artcileStereoselective synthesis of E or Z α-methyl α,β-ethylenic esters from phosphonates or phosphine oxides by the Wittig-Horner reaction, COA of Formula: C5H12BrO3P, the publication is Tetrahedron (1984), 40(24), 5153-66, database is CAplus.
The reaction of α-branched aldehydes with (EtO)2P(O)CHMeCO2Me in THF/BuLi at low temperature leads stereoselectively to Z α-Me α,β-unsaturated esters. From a linear aldehyde, the reaction is less stereoselective, while from α,β-unsaturated ones, the E isomers are predominantly formed in good yields. From Ph2P(O)CHMeCO2Me, E α-Me α,β-unsaturated esters are stereoselectively formed either in DMF/Me3COK or under phase transfer conditions, regardless of the starting aldehyde. This reagent can thus advantageously replace the corresponding P-ylide.
Tetrahedron published new progress about 66197-72-6. 66197-72-6 belongs to bromides-buliding-blocks, auxiliary class Aliphatic Chain, name is Diethyl (bromomethyl)phosphonate, and the molecular formula is C5H12BrO3P, COA of Formula: C5H12BrO3P.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary