Grignard reagent, reaction with alcohol

The alcohol intermediate happens to be the exact kind of intermediate that was produced by the Grignard reagent reaction with propanal to produce isosafrole back-a-ways in the big chapter. So what the chemist does is apply the 1g of KHSO4 to that crude alcohol intermediate and process it just as was done before to give isosafrole, or propenylbenzene or 3,4-methylenedioxyphenyl -1-butene or phenylbutene (yield=91% ). This is a great little procedure. 

The mam synthetic application of Grignard reagents is their reaction with certain carbonyl containing compounds to produce alcohols Carbon-carbon bond formation is rapid and exothermic when a Grignard reagent reacts with an aldehyde or ketone... 

Alcohol synthesis via the reaction of Grignard reagents with carbonyl com pounds (Section 14 6) This is one of the most useful reactions in synthetic organ ic chemistry Grignard reagents react with formaldehyde to yield primary alco hols with aldehydes to give secondary alcohols and with ketones to form terti ary alcohols... 

The various Grignard reagents react with a variety of aldehydes and ketones to yield primary alcohols (yield, 27 6%), secondary alcohols (yield, 13 1-71 1%), and tertiary alcohols (yield, 24 9-81 7%) Products of the reactions with acetone are given in Table 4... 

Reaction of organolithium reagents with aldehydes and ketones (Section 14.7) Organolithium reagents react with aldehydes and ketones in a manner similar to that of Grignard reagents to form alcohols. 

Grignard reagents react with oxetane, a four-membered cyclic ether, to yield primary alcohols, but the reaction is much slower than the corresponding reaction with ethylene oxide. Suggest a reason for the difference in reactivity between oxetane and ethylene oxide. 

Reaction of Acid Chlorides with Organometallic Reagents Grignard reagents react with acid chlorides to yield tertiary alcohols in which two of the substituents are the same. 

The low yields, which are observed among styrenyl adducts, reflect a combination of the poor reactivity of the styrene at the low temperature of the reaction. For example, the combination of t-butyl Grignard with the 2,4-bis-OBoc-benzyl alcohol 15 affords the corresponding benzopyran 50 in only 50% yield even when carried out in the presence of 5-10 equivalents of the styrene (method H, Fig. 4.27).27 Yields for substituted benzopyran styrene adducts are still lower (method G, Fig. 4.27). For example, addition of methyl lithium to 2,4-bis-OBoc-benzylaldehyde 5 followed by the addition of the dienophile and magnesium bromide affords benzopyran 51 in a paltry 27% yield. Method F is entirely ineffective in these cases, because the methyl Grignard reagent competes with the enol ether and with styrene 1,4-addition of methyl supercedes cycloaddition. 

Cumylamine, oxidation of, 323 Cupferron ammonium salt, 447 reaction with Grignard reagents, 352 free acid, 402 Cyanamides, 161 reaction with alcohols, 174 Cyanoallene, 24... 

Reaction with aldehydes Grignard reagents react with aldehydes (R CH=0) to give secondary alcohols. 

The reaction of esters with Grignard reagents and with lithium aluminum hydride, both useful in the synthesis of alcohols, were described earlier. They are reviewed in Table... 

Vinyl Grignard reagent reacts with the aldehyde function in the open-chain form of compound 6. leading initially to diol 25 with a diastereoselectivity of 71 2 antr.syn). The diasteromeric alcohols atn be separated after silylation to 7, but this is unnecessary since both isomers lead to the same product in the subsequent reaction. 

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