Tetrahydrofuranyl ethers, synthesis

Although alcohols are oxidized by tetra-n-butylammonium persulphate when the reaction is conducted in dichloromethane, tetrahydropyranyl ethers have been produced (>90%) when attempts to oxidize the alcohol are conducted in tetrahydro-pyran (see Chapter 10) [ 19], Tetrahydrofuranyl ethers have been prepared by an analogous method [20,21 ]. Base-mediated elimination of halo acids from P-halo alcohols under phase-transfer catalysed conditions produce oxiranes in high yield (70-85%). The reaction has particular use in the synthesis of epihalohydrins from p,y-dihalo alcohols [22],... 

Tetrahydropyranyl (TUP) and tetrahydrofuranyl ethers are important protecting groups for alcohols and phenols in organic synthesis, but they can also be converted to other useful functional groups [8, 118]. For example, allylation of a TUP ether should yield a highly functionalized molecule (Scheme 15). 

Krabbe SW, Angeles VV, Mohan RS (2010) Bismuth(III) bromide in organic synthesis. A catalytic method for the allylation of tetrahydrofuranyl and tetrahydropyranyl ethers. Tetrahedron Lett 51 5643-5645... 

Full details have been disclosed of the synthesis of 2-tetrahydrofuranyl (THF) ethers (57) (Scheme 30) from either 2-chlorotetrahydrofuran (basic conditions) or the stable, solid, acetal ester (58) (acidic conditions). THF ethers are more basic... 

---