Lead!IV acetate

Chemical Designations - Synonyms Lead (IV) acetate Chemical Formula Pb(C2H302)4-CH3COOH. Observable Characteristics - Physical State (as shipped) Crystals wet with glacial acetic acid Color Faintly pink Odor Like acetic acid or vinegar. 

Two percent to saturated solution of lead(IV) acetate in glacial acetic acid. 

The reaction is based, on the one hand, on the oxidative cleavage of vicinal diols by lead(IV) acetate and, on the other hand, on the reaction of dichlorofluorescein with lead(IV) acetate to yield a nonfluorescent oxidation product. The dichlorofluorescein only maintains its fluorescence in the chromatogram zones where the lead(IV) acetate has been consumed by the glycol cleavage reaction [1],... 

Dipping solution I Dissolve 1 g lead(IV) acetate (lead tetraacetate) in 100 ml ethanol. 

The reaction depends, on the one hand, on the fact that fuchsin is decolorized by oxidizing agents (e.g. lead(IV) acetate) and, on the other hand, on the fact that lead(IV) acetate is reduced by compounds containing a-diol groups. It is, therefore, no longer available to decolorize the fuchsin. The fuchsin undergoes a Schiff reaction with the aldehydes that are formed [2]. 

Note The color of the zones persists for a long period, but changes to blue-violet [1]. Rosaniline [1, 2] can be employed instead of fuchsin. With sugar alcohols lead(IV) acetate alone yields white zones on a brown background (detection limit 1 — 2 pg per chromatogram zone) [3]. 

The method for the synthesis of 1,2,4-tiiazine 4-oxides 55 involving the condensation of isonitrosoacetophenone hydrazones with aldehydes followed by the oxidation of the intermediates 87 with lead(IV) acetate was reported above (97MC238, 98ZOR423). 

Even with the highly reactive dienophile cyclohepta-2,6-dien-4-ynone, generated from 1-aminocycloheptatriazol-6-(1 H)-one by lead(IV) acetate oxidation, only the adduct of benzene oxide 3 can be isolated.231... 

Amino-77/-dibenz[/),t/]azepin-7-ones, e.g. 7, prepared either by successive bromination, aminodebromination, and dehydrogenation of 5-tosyl-5A/-dihydro 7>,t/]azepin-7(6//)-ones, or by the oxidation of 6-ethoxy-6,7-dihydro-5//-dibenz 7>,r/]azepincs with lead(IV) acetate followed by aminodemethoxylation, on treatment with a bidentate nucleophile (e.g.. benzene-1,2-diamine or 2-aminobenzenethiol) yield the pentacyclic systems 8 and 9, respectively.27... 

Methyl l//-l,2-benzodiazepine-3-carboxylate (1) reacts with lead(IV) acetate to give the 5-acetoxy-5//-1,2-benzodiazepine 2, which is converted into the 1//-tautomer 3 in the presence of triethylamine in benzene. Further treatment of 3 with triethylamine in methanol results in hydrolysis to yield the benzodiazepinone 4. 25... 

The 1/7-1,2-benzodiazepines 6 react with lead(IV) acetate to give 3-acetoxy-3//-l, 2-benzo-diazepines 5 with mcthanolic copper(II) nitrate, the 3-methoxy-3//-l,2-benzodiazepines 7 arc formed.123... 

The 7-bromo-5-(2-pyridyl)diazepinone 18 reacts with lead(IV) acetate to yield the 3-acetoxy derivative 19, which is converted into the 3-hydroxy compound 20 by the action of sodium methoxide, followed by water.201... 

N-Aminobenzoxazolin-2-one (4), which was readily prepared by animation of benzoxazolin-2-one with hydroxylamine-O-sulfonic acid, is also a useful nitrene precursor (Scheme 2.2). Oxidation of 4 with lead(iv) acetate in the presence of a conjugated diene resulted in exclusive 1,2-addition of nitrene 5, to yield vinylazir-idine (6) in 71 % yield [6]. The formation of vinylaziridines through 1,2-additions of methoxycarbonylnitrene (2) or amino nitrene 5 contrasts with the claimed 1,4-ad-dition of nitrene itself to butadiene [7]. Since the reaction proceeded stereospecif-ically even at high dilution, the nitrene 5 appears to be generated in a resonance-stabilized singlet state, which is probably the ground state [8]. 

Lactams, 70, 71,73, 112 LDMAN, see Lithium 1-dimethylamino-naphthalenide Lead(iv) acetate, 115... 

A mixture of lead(iv) acetate (20 mmol) and KOAc (100 mmol) in AcOH (30 ml) was treated with the neat aldehyde-derived silyl enol ether (20mmol) at ambient temperature. After being stirred for 1 h at ambient temperature, the reaction mixture was diluted with water (30ml), and then extracted with pentane (3 x200ml). The combined pentane extracts were washed with saturated sodium hydrogen carbonate solution (2x50ml), dried, concentrated and distilled to give the product a-acetoxyaldehyde (45-78%). 

Comparative reactions of nitrogen compounds with the isoelectronic series, mercury(II), thal-lium(III) and lead(IV) acetates. Principles of oxidation reactions. R. N. Butler, Chem. Rev., 1984, 84, 249-276 (307). 

Lead(IV) acetate cleaves organic diols such as 2,3-dihydroxy-2,3-dimethylbutane in aqueous solution to give ketones. Write the overall reaction for the following proposed mechanism and identify any reaction intermediates ... 

Alcohols (diols, polyols, sugan) Lead(IV) acetate -dichloro fluorescein Diol cleavage of vicinal diols, e. g. sugars, sugar alcohols. The lead tetraacetate consumed is no longer available to decompose the fluorescent dichlorofluorescein. [3, 8]... 

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