Diol monotosylates ethers, cyclic

Cyclic ethers from diol monotosylates 236. HOv. ..CH2CH2OTS... 

Bouzide, A. Sauve, G. Silver(I) oxide mediated highly selective monotosylation of symmetrical diols. Application to the synthesis of poly-substituted cyclic ethers. Org. Lett. 2002, 4, 2329-2332. 

Selective monotosylations of symmetrical diols have been accomplished in good yields (75-93%) with a stoichiometric amount of tosyl chloride in the presence of Ag(I) oxide and a catalytic amount of potassium iodide. When excess Ag(I) oxide is used, polysubstituted cyclic ethers are formed in 61-88% yield. This method was also used for the synthesis of substituted crown ethers. 

Selective monotosylation of symmetric diols was also reported. i This technique was further applied to the s)mthesis of cyclic ethers (eq 22). This process, performed in the presence of at least 3 equiv of Ag20, was particularly favorable when steri-cally undemanding five- or six-membered rings could be formed. However, the technique was also used for the formation of the three-membered oxirane ring and of a substituted 5-0-crown ether. 

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