A practical total synthesis of plaunotol via highly Z-selective Wittig olefination of 濞?acetal ketones was written by Tago, Keiko;Arai, Masami;Kogen, Hiroshi. And the article was included in Perkin 1 in 2000.Synthetic Route of C23H26BrP This article mentions the following:
Plaunotol, a known antiulcer drug, is the most important component of the Thai folk medicinal plant, Plau-noi, which has remarkable antipeptic ulcer activity. Recently, it was found that plaunotol has antibacterial activity against Helicobacter pylori, a causative agent in gastric ulcers and gastric adenocarcinoma, for example. In the investigation of the practical synthesis of plaunotol, the authors have developed an efficient method for stereoselective synthesis of trisubstituted olefins via a Z-selective Wittig reaction. The olefination of readily available aliphatic 濞?acetal ketones with triphenylphosphonium salts in the presence of a potassium base and 18-crown-6 ether proceeded with excellent Z-selectivity. The Z-selective olefination provides a useful method for the construction of a range of trisubstituted olefin moieties; the practical and stereoselective total synthesis of plaunotol was achieved via this Wittig reaction. In the experiment, the researchers used many compounds, for example, Isopentyltriphenylphosphonium bromide (cas: 28322-40-9Synthetic Route of C23H26BrP).
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闁艰京鐗梤omine bond is electrophilic in nature. When the molecular ion is detected, the bromine and chlorine isotope patterns are very distinct, but caution is to be exercised for certain mixed chlorinated/brominated compounds, which can look similar to homohalogen patterns.Synthetic Route of C23H26BrP
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary