O-allyl derivative

Aryl diazonium ions are converted to iodides in high yield by reaction with iodide salts. This reaction is initiated by reduction of the diazonium ion by iodide. The aryl radical then abstracts iodine from either I2 or I3. A chain mechanism then proceeds which consumes I- and ArN2+.105 Evidence for the involvement of radicals includes the isolation of cyclized products from o-allyl derivatives. 

The allyl ethers of phenols may be converted via a Claisen rearrangement to o-allyl derivatives and thence to the benzo[6]furans. The products of addition of bromine to the o-allylphenols give good yields of the heterocycle on prolonged heating with alkali, but the photochemical rearrangement of O-allylphenol is not so effective. 

Sodium hydroxide-induced partial allylation was used for preferential reaction at the equatorial OH-4 in l,6-anhydro-2-0-benzyl-P-D-galactopyranose [229]. A similar reaction of allyl 2,6-di-O-benzyl-a-D-galactopyranoside with allyl bromide and sodium hydroxide in benzene at room temperature was not as regioselective, the per-substituted 3,4-di-O-allyl derivative dominated in the reaction product [73]. A high, 87 % yield of the monoallyl derivative was obtained from 1,2 5,6-di-O-isopropylidene-D-mannitol after the treatment with allyl bromide and sodium hydroxide in aqueous acetone [230],... 

During the course of studies on the allylation of 5,6-0-isopropylidene-L-ascorbic acid (152), it was shown that the 3-0-allyl derivative 163 was formed in high yield by reaction of 152 with allyl bromide and K2C03 in dimethyl sulfoxide at room temperature.357 It was later shown that the 3-O-allyl derivative (163) can rearrange to the thermodynamically more stable 2-C-allylated products (164, 165) in a time- and temperature-dependent manner.358... 

Mono-O-allyl derivative of 1,6-hexanediol undergoes RuCl2(PPh3)3-catalyzed isomerization to give 2-ethyl 1,3-dioxonane <2004SL1203>. 

The Chemical Shifts of Some o-Allylic Derivatives of Some Metals and Metalloids MCiH2C H=C >Ha... 

Recently, an additional version of intramolecular aglycone delivery starting from 2-O-allyl derivatives and using iodonium ion-promoted tethering was described [83]. As illustrated in Scheme 5.28, the 2-(9-allyl ether (154) was first isomerized to the propenyl ether (155). NIS-promoted coupling with the acceptor (146) then afforded the mixed acetal (156), which was transformed into the (3-mannoside (148) by using NIS and AgOTf for activation. 

Several of these compounds appear in the Merck Index. The (3-blocking oxprenolol, the arylacetic analgesic-antiinflammatory dmg aclofenac and the fungicide enilconazole are O-allyl derivatives. Penicillin O and penicillin S are both S-allyl derivatives. 

Mono-O-allyl derivatives of o-fructose have been prepared in order to test the specificity of the fructose transporter GLUT5. Tris(triphenylphosphine)ruthe-nium(II) dichloride is an excellent catalyst for the isomerization of allyl to prop-l-enyl ethers in a de-O-allylation procedure. The catalyst avoids the problem of reduction of the alkene as a side reaction. " Another method uses Pd(0)-catalysed allyl transfer to p-toluenesulfinic acid for the cleavage of allyl ethers on a solid support."... 

Propenyl from O-allyl derivatives OCHgCH CHg OCH CHCHg... 

A new efficient and stereoselective synthesis of furo[2, 3 5,6]pyrano[4,3-i)]quinoline derivatives and has been achieved by intramolecular hetero Diels-Alder reactions of aldimines generated in situ from aromatic amines and the O-allyl derivative of the chiral sugar derived aldehyde in acetonitrile in the presence of a catalytic amount (10 mol%) of BiCl3. The products are formed with extremely high (>95%) trans-selectivity in good to excellent yields (Equation 20) [38a]. The authors have also carried out the diastereoselective synthesis of new hexahydropyrazolo[4, 3 5,6]thiopyrano[4,3-t>] in the similar conditions [38b]. 

O-Propenyl from O-allyl derivs. OCH2CH CH, OCH CHCH ... 

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