Abstract:Notes net, was difficult. Only by repeated recrystallizations from alcohol under nitrogen ivas an analytically pure sample obtained. The oxazine was stable in the solid state, but was unstable in certain solutions (e.g., benzene or hexane), particularly in the presence of oxygen. No pure compounds have been isolated from this decomposition.Compound 2 wTas unreactive tow-ard NaBH4 and reacted only partially with LiAlH4 in pyridine or boiling alcoholic KOH. As expected, reaction with acid occurred readily. Howev… Show more
The molecular structures and spectral properties of α-haloketones as well as their syntheses are analyzed and reviewed. Their reactivity towards oxygen, nitrogen, and sulfur nucleophiles, carboxylic acids, carbon nucleophiles, alkenes, and alkynes are discussed.
The molecular structures and spectral properties of α-haloketones as well as their syntheses are analyzed and reviewed. Their reactivity towards oxygen, nitrogen, and sulfur nucleophiles, carboxylic acids, carbon nucleophiles, alkenes, and alkynes are discussed.
“…Trialkyl phosphites (RO) 3 P are known to react with α-haloketones to yield 318 (Arbusov reaction) (Eq 11)[610][611][612][613][614][615][616][617][618][619][620][621][622][623][624].In general, the attack of phosphites can take place at four positions: (1) attack on the carbon atom carrying the halogen giving rise to an enol phosphate 319 or to a β-ketophosphonate 320; (2) attack on the carbonyl oxygen; (3) attack on the carbonyl carbon, giving rise to an epoxyphosphonate 321 or a vinyl phosphate 319; (4) attack on the halogen, furnishing the enol phosphate 319 (Scheme 92).…”
The preparation of vinyl (or enol) phosphates from α‐halo carbonyl compounds and trivalent phosphorus reagents and is generally known as the Perkow reaction. The study finds that, α‐halo aldehydes are more reactive than α‐halo ketones; whereas α‐halo esters are the least reactive species for the Perkow reaction, and α‐halo amides do not react at all. It has been found that the more α‐halo atoms in the carbonyl compound, the faster the reaction occurs. All the suitable reagents have been suggested for this reaction
Both the electronic character of phosphorus and the steric effects are prominent in the Perkow reaction, as indicated by the predominant
trans
‐configuration in vinyl phosphates. It is observed that the course of the reaction depends on the nature and position of halogen on the carbonyl compounds as well as the reaction temperature. This reaction has importance for the preparation of vinyl phosphates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.