In 2019,Journal of the American Chemical Society included an article by Zhou, Shupeng; Xia, Kaifu; Leng, Xuebing; Li, Ang. Synthetic Route of C19H18BrP. The article was titled 《Asymmetric Total Synthesis of Arcutinidine, Arcutinine, and Arcutine》. The information in the text is summarized as follows:
We have accomplished the asym. total synthesis of arcutinidine, arcutinine, and arcutine, three arcutine type C20-diterpenoid alkaloids. A pentacyclic intermediate was rapidly assembled by using two Diels-Alder reactions. We developed a cascade sequence of Prins cyclization and Wagner-Meerwein rearrangement to construct the core of arcutinidine, which was then elaborated into an oxygenated pentacycle through a scalable route. Chemoselective reductive amination followed by spontaneous imine formation furnished the pyrroline motif at a final stage. We clarified the S configuration of the α-carbon of the acyl group within arcutine through chem. synthesis and crystallog. anal. In the part of experimental materials, we found many familiar compounds, such as Methyltriphenylphosphonium bromide(cas: 1779-49-3Synthetic Route of C19H18BrP)
Methyltriphenylphosphonium bromide(cas: 1779-49-3) is used for methylenation through the Wittig reaction. It is utilized in the synthesis of an enyne and 9-isopropenyl -phenanthrene by using sodium amide as reagent. Synthetic Route of C19H18BrP
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary