Oxidation of allyl alcohols

By-product acetic acid is obtained chiefly from partial hydrolysis of cellulose acetate [9004-35-7]. Lesser amounts are obtained through the reaction of acetic anhydride and cellulose. Acetylation of saHcyHc acid [69-72-7] produces one mole of acetic acid per mole of product and the oxidation of allyl alcohol using peracetic acid to yield glycerol furnishes by-product acid, but the net yield is low. 

In comparison with manganese dioxide, the DDQ reagent has several advantages for the oxidation of allylic alcohols. The quinone method is more reproducible only one equivalent of oxidant need be added and generally fewer side reactions are observed. On the other hand, the workup of DDQ reactions often requires chromatography and in the simpler cases lower isolated yields may be realized. 

Nickel peroxide is a solid, insoluble oxidant prepared by reaction of nickel (II) salts with hypochlorite or ozone in aqueous alkaline solution. This reagent when used in nonpolar medium is similar to, but more reactive than, activated manganese dioxide in selectively oxidizing allylic or acetylenic alcohols. It also reacts rapidly with amines, phenols, hydrazones and sulfides so that selective oxidation of allylic alcohols in the presence of these functionalities may not be possible. In basic media the oxidizing power of nickel peroxide is increased and saturated primary alcohols can be oxidized directly to carboxylic acids. In the presence of ammonia at —20°, primary allylic alcohols give amides while at elevated temperatures nitriles are formed. At elevated temperatures efficient cleavage of a-glycols, a-ketols... 

Oppenauer oxidation, 236 Oxidation of allylic alcohols with dichloro-dicyanobenzoquinone, 248 Oxidation of allylic alcohols with manganese dioxide, 247... 

For the oxidation of allylic alcohols to alkene aldehydes, also see Section 48 (Aldehydes from Alcohols). 

The very fast oxidation of the radical precludes its detection and identification by esr however, reacting mixtures are capable of initiating polymerisation of acrylonitrile. The oxidations of allylic alcohols by V(V) perchlorate are ca. thirty times faster than those of saturated alcohols. This is supporting evidence for radical intermediates in view of the expected delocalisation of the free electron... 

Manganese dioxide has been nsed to carry out a range of chemical oxidations, and is the reagent of choice for the oxidation of allylic alcohols (Hndlicky 1990). There are several methods for its preparation that may acconnt for differences in its activity. Although it has seldom been exploited for the oxidation of contaminants, two widely different applications have been described ... 

The oxidation of allyl alcohol shows an interesting pH dependence (144,147). When the pH < 2.0, the main product is acrylaldehyde and the rate is independent of, or inversely proportional to [H+], with the catalysts Ru(III) and Ru(EDTA), respectively.5 In this case, hydride... 

Additional results of the enhancement in phenol conversion (to dihydroxy benzenes) and oxidation of allyl alcohol (to glycidol and allylic oxidation products) catalyzed by TS-1 in various solvents are illustrated in Fig. 46. In solvents with high dielectric constants, the heterolytic cleavage of the 0-0 bond... 

Figure 1.3 Oxidation of allylic alcohol using Ti(0 — z -Pr)4, TBHP and tartrate ligand.

Selective oxidation of allylic alcohols.1 This zircononcene complex when used in catalytic amount can effect an Oppenauer-type oxidation of alcohols, including allylic ones, in the presence of a hydrogen acceptor, usually benzaldehyde or cyclohexanone. This system oxidizes primary alcohols selectively in the presence of secondary ones. Thus primary allylic alcohols are oxidized to the enals with retention of the configuration of the double bond in 75-95% yield. The method is not useful for oxidation of propargylic alcohols. 

Oxidation of allylic alcohols and enones.3 These substrates are cleaved to dicarboxylic acids and keto acids by Sharpless catalytic Ru02 oxidation. Examples ... 

Scheme 4 Oxidation of allyl alcohol at the nickel oxide electrode.

Takeya K, Itokawa H, Stereochemistry in oxidation of allylic alcohols by cell-free system of callus induced from Canabis sativa L., Chem Pharm Bull (Tokyo),... 

Interestingly, solution studies on the namre of the active catalyst, carried out in the case of Ti(IV)-tartrate catalysts proposed by Katsuki and Sharpless for the enantioselective oxidation of allylic alcohols, opened routes to enantioselective oxidations of thioethers . ... 

Alkynylepoxy alcohols of high enantiomeric purity, obtained via Sharpless oxidation of allylic alcohols (see Section D.4.5) react smoothly with excess dialkylcuprate/magnesium bromide to give (/Vf.25)-3.4-alkadiene-1.2-diols in reasonable overall yield and with high anti selectivity when performed at low temperature and by using the dimethyl sulfide complex of copper(I) bromide to synthesize the cuprates42. 

Selective oxidation of allylic alcohols.2 PCC in CH2C12 containing pyridine (2%) selectively oxidizes steroidal equatorial allylic hydroxyl groups. PCC buffered with... 

XI. Selective Oxidation of Allylic Alcohols / 244 Manganese dioxide / 244 Dichlorodicyanobenzoquinone / 247 Nickel peroxide / 248... 

Activated manganese dioxide, which is generally used for the selective oxidation of allylic alcohols, permitted the synthesis of an unsaturated (3-keto-arabino-hexopyranosyl)pyridine.13 New oxidative systems for alcohols, involving molecular sieve-assisted... 

Oxidation of allylic alcohols.1 Allylic alcohols are oxidized to the corresponding enones in 80-95% yield by PCC complexed with benzotriazole (CH2C12, 23°). 

Oxovanadium(V) and oxomolybdenum(VI) were incorporated into crosslinked polystyrene resins functionalized with iminodiacetic acid or diethylenetriamine derivatives 921 The polymer complexes were used as catalysts in the oxidation of olefins with f-butylhydroperoxide. Vanadium(V) complexes promote the epoxidation of allylic alcohols in a highly regioselective manner, e.g., 2,3-epoxide was obtained in 98 % selectivity from e-geraniol at 80 °C. The catalytic activity of the vanadium(V) complexes is generally higher than that of the molybdenium(VI) complexes in the oxidation of allylic alcohols, whereas an opposed trend holds for the epoxidation of cyclohexene. 

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