CHAPTER FIFTEEN Alcohols, Diols, and Thiols gnard reagents react with ethylene oxide to yield primary alcohols containing two carbon atoms than the alkyl halide from which the organometallic compound was prepared RMgX HC CH RCH, CH,OH Grignard Ethylene oxide Primary alcohol CH3(CH2)4CH,MgBr H2C-CH2-0 u >CH3(CH2)4CH2CH2,OH Hexylmagnesium Ethylene oxide Octanol (71%) Organolithium reagents react with epoxides in a similar manner. PROBLEM 15.4 Each of the following alcohols has been prepared by reaction of a Grignard reagent with ethylene oxide. Select the appropriate Grignard read nt in each case TCH2CH2OH SAMPLE SOLUTION (a)Reaction with oxide results in the addition of a - CH,OH unit to the grignard rea Grignard reagent derived from O-bromotoluene(or o-chlorotoluene or o luene)is appropriate here Hc、ch2 CHCHOH o-Methylphenylmagnesium Ethylene oxide 2(o-Methylphenyl)ethanol bromide (66%) Epoxide rings are readily opened with cleavage of the carbon-oxygen bond when attacked by nucleophiles. Grignard reagents and organolithium reagents react with eth ylene oxide by serving as sources of nucleophilic carbon RM2x→RcH2-CH2-0Mx→p RCH2 CH2OH HoC-CH ( may be written as RCH,CH,OMgX This kind of chemical reactivity of epoxides is rather general Nucleophiles other than Grignard reagents react with epoxides, and epoxides more elaborate than ethylene oxide may be used. All these features of epoxide chemistry will be discussed in Sections 16.11 d16.12 Back Forward Main MenuToc Study Guide ToC Student o MHHE WebsiteGrignard reagents react with ethylene oxide to yield primary alcohols containing two more carbon atoms than the alkyl halide from which the organometallic compound was prepared. Organolithium reagents react with epoxides in a similar manner. PROBLEM 15.4 Each of the following alcohols has been prepared by reaction of a Grignard reagent with ethylene oxide. Select the appropriate Grignard reagent in each case. (a) (b) SAMPLE SOLUTION (a) Reaction with ethylene oxide results in the addition of a ±CH2CH2OH unit to the Grignard reagent. The Grignard reagent derived from o-bromotoluene (or o-chlorotoluene or o-iodotoluene) is appropriate here. Epoxide rings are readily opened with cleavage of the carbon–oxygen bond when attacked by nucleophiles. Grignard reagents and organolithium reagents react with eth￾ylene oxide by serving as sources of nucleophilic carbon. This kind of chemical reactivity of epoxides is rather general. Nucleophiles other than Grignard reagents react with epoxides, and epoxides more elaborate than ethylene oxide may be used. All these features of epoxide chemistry will be discussed in Sections 16.11 and 16.12. R MgX RCH2CH2OH   H2C O CH2 R CH2 MgX CH2 O  (may be written as RCH2CH2OMgX) H3O CH3 MgBr o-Methylphenylmagnesium bromide H2C O CH2 Ethylene oxide 1. diethyl ether 2. H3O CH3 CH2CH2OH 2-(o-Methylphenyl)ethanol (66%) CH2CH2OH CH3 CH2CH2OH 1. diethyl ether 2. H3O RMgX Grignard reagent H2C O CH2 Ethylene oxide RCH2CH2OH Primary alcohol 1. diethyl ether 2. H3O H2C O CH2 Ethylene oxide CH3(CH2)4CH2MgBr Hexylmagnesium bromide CH3(CH2)4CH2CH2CH2OH 1-Octanol (71%) 588 CHAPTER FIFTEEN Alcohols, Diols, and Thiols Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website