Benzyl alcohol, derivative

Benzyl-derived quaternary ammonium compounds are used widely as cationic surface-active agents and as germicides, fungicides, and sanitizers. Benzyl alcohol is used in a wide spectmm of appHcations including pharmaceuticals and perfumes, as a solvent, and as a textile dye assistant. 

The availability of non-racemic oxepins through tandem catalytic RCM and Zr-catalyzed kinetic resolution has additional important implications. Optically pure heterocycles that carry a heteroatom within their side chain (cf. (S)-14 in Scheme 3) can be used in stereoselective uncatalyzed alkylations. The alcohol, benzyl ether or MEM-ethers derived from (S)-14 readily undergo directed [10] and diastereoselective alkylations when treated with a variety of Grignard reagents [11]. 

The availability of oxepins that bear a side chain containing a Lewis basic oxygen atom (entry 2, Table 6.4) has further important implications in enantioselective synthesis. The derived alcohol, benzyl ether, or methoxyethoxymethyl (MEM) ethers, in which resident Lewis basic heteroatoms are less sterically hindered, readily undergo diastereoselective uncatalyzed alkylation reactions when treated with a variety of Grignard reagents [17]. The examples shown below (Scheme 6.7) demonstrate the excellent synthetic potential of these stereoselective alkylations. 

The reaction appeared complete by TLC (silica, diethyl ether - petroleum ether, 1 1) Rf alcohol = 0.15, Rf O-benzyl derivative = 0.27. 

Thermolysis in benzyl alcohol of 4-diazopyrazole 22b gave the corresponding 4-benzyl derivative [60CI(L)659]. The reaction goes through the... 

Benzyl alcohol and derivs 2 B91— B92 benzyl nitrate 2 B91 benzyl nitrite 2 B91 dinitrobenzyl alcohol 2 B91 dinitrobenzyl nitrate 2 B92 mononitrobenzyl alcohol 2 B91 mononitrosobenzyl alcohol 2 B91 nitrobenzyl dinitrate 2 B91-B92 nitrobenzyl nitrate 2 B91 trinitrobenzyl alcohol 2 B92... 

Historically, this represents the first thiophene synthesis, when Laurent obtained tetraphenylthiophene by heating polymeric thiobenzaldehyde in 1844. Almost any aromatic methyl derivative can be converted to tetraphenylthiophene, which is thermodynamically the most stable thiophene, by heating with sulfur. Toluene, phenylacetic acid, benzyl alcohol, benzyl sulfide or disulfide, benzyl sulfonate or even sodium thiobenzoate have been converted to tetraphenylthiophene under these conditions (52HC(3)l). 

L-Rhodinose (174) was prepared from the readily available L-rhamnose.269 The method required deoxygenation of C-2 and C-3 and inversion of configuration at C-4 (Scheme 56). Oxidation of 187 with ruthenium dioxide-IOj, followed by reduction of the keto groups with lithium aluminum hydride yielded the alcohol 188. After protection as the benzyl derivative, an alkenic linkage was... 

Benzyl derivatives of aliphatic alcohols 73> are not reduced below the discharge potential of (C2H5)4N + in DMF [—2.9 V(SCE)]. But, they show a wave around —3.1 V(SCE) in solutions of (C4H9)4N+. Efficient reductive cleavage of benzyl methyl ether was achieved n) in THF-8% H20 with 0.25 M (C4H9)4NBF4. Under these conditions, toluene, which is the cleavage product may also be reduced and the... 

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