Alcohols to Alkylating Agents

The cychc haUdes can be converted to discrete substitution products by reaction with amines, alcohol, or alkylating agents. For example, (NPCl ) reacts with ammonia to form (NP(NH2)2)3 [13597-92-7] withy -NaOCgH CH to form (NP(OCgH4CH2)2)3 [27122-73-2] and with CH MgCl to form (NP(CH3)2)3 [6607-30-3]. Among the cychc members, the trimeric haUdes are the most inert toward substitution and tetrameric haUdes are the most active. 

Trichloroacetimidates are the only type of imino ethers to have found some application in solid-phase synthesis. Trichloroacetimidates can readily be prepared from support-bound alcohols by treatment with trichloroacetonitrile and a base (Entry 6, Table 13.18). Because trichloroacetimidates are good alkylating agents, this reaction offers a convenient alternative for converting support-bound aliphatic alcohols into alkylating agents. Trichloroacetimidates prepared from Wang resin or from hydroxymethyl polystyrene are quite stable and can be stored for several months without decomposition [253],... 

Data for the use of alcohols as alkylating agents in superacids are scarce. A study of the alkylation of phenol and naphthols with ferf-butyl alcohol has shown198 that triflic acid adsorbed on aminopropyl-modified silica is the most selective to yield monoalkylated products compared to solid acids (triflates immobilized in silica). 

O-Alkylation of alcohols with alkylating agents is a practical method not only for the synthesis of unsymmetrical ethers (16), but also for protecting hydroxyl groups (17). The alkylation reactions are usually conducted under strongly basic conditions via the formation of alkoxides from alcohols. However, an alternative method performed under neutral conditions would be desirable for the conversion of alcohols that are sensitive to strong bases. 

Risk factors associated with childhood AML include Hispanic ethnicity, prior exposure to alkylating agents or epipodophyllotoxins, and in utero exposure to ionizing radiation. Maternal alcohol consumption, parental and child pesticide exposure, and parental benzene exposure are also potential risk factors for childhood AML. 

Methyl 7-hydroxyhept-5-ynoate is an important precursor to alkylating agents that are used to Introduce the complete prostaglandin a-s1de chain.It is normally prepared from propargyl alcohol using a six-step sequence originally introduced by Corey and Sachdev with subsequent modifications.Alternative routes to methyl 7-hydroxyhept-5-ynoate have also been reported but appear less efficient than the one described here. 

Friedel-Crafts Alkylation. The Friedel-Crafts alkylation of arenes with benzyl alcohol as alkylating agent has been investigated with Hf(OTf)4 supported on MCM-41. The catalytic activity of Hf(OTf)4 was enhanced by loading onto MCM-41 due to increased dispersion and gave the benzylated product in high yield. The system was reusable without loss of activity. 

The hydroxyl groups can be alkylated with the usual alkylating agents. To obtain aryl ethers a reverse treatment is used, such as treatment of butynediol toluenesulfonate or dibromobutyne with a phenol (44). Alkylene oxides give ether alcohols (46). 

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