1126-35-8Relevant academic research and scientific papers
Allylic and allenic halide synthesis via NbCl5- and NbBr 5-mediated alkoxide rearrangements
Ravikumar,Yao, Lihua,Fleming, Fraser F.
supporting information; experimental part, p. 7294 - 7299 (2010/01/16)
(Chemical Equation Presented) Addition of NbCl5 or NbBr 5 to a series of magnesium, lithium, or potassium allylic or propargylic alkoxides directly provides allylic or allenic halides. Halogenation formally occurs through a metallahalo-[3,3] rearrangement, although concerted, ionic, and direct displacement mechanisms appear to operate competitively. Transposition of the olefin is equally effective for allylic alkoxides prepared by nucleophilic addition, deprotonation, or reduction. Experimentally, the niobium pentahalide halogenations are rapid, afford essentially pure (E)-allylic or -allenic halides after extraction, and are applicable to a range of aliphatic and aromatic alcohols, aldehydes, and ketones. 2009 American Chemical Society.
Intramolecular Cyclization of Nerol and the Related Attack of (Z)-Allylic Alcohol Moiety on the Terminal Olefin Linkage as Induced by TiCl4-PhNHMe Complex. Synthesis of Nezukone
Itoh, Akira,Saito, Tadashi,Oshima, Koichiro,Nozaki, Hitosi
, p. 1456 - 1459 (2007/10/02)
Nerol was cyclized to terpinyl chloride or bromide in the presence of TiX4-PhNHMe (1:1) complex (I, X=Cl, Br) in dichloromethane at -23 deg C, geraniol being converted into geranyl halide by simple halogenation.Terminally modified derivatives YCH2C(Me)=CHCH2CH2CMe=CHCH2OH (Y=SiMe3, SnBu3) of (2Z,6E) configuration were cyclized by treatment with I to afford limonene in high yields and 100percent selectivity.Cyclization of (2Z) isomers of CH2=CR-CH2CH2CMe=CHCH2OH (R=H, Me, Cl) produced seven-membered carbocyclic products in fair yields.The novel procedure has been utilized in the synthesis of nezukone from (2E)-3-isopropyl-2,6-heptadien-1-ol involving five steps.
