Cannizzaro intramolecular

The slow, rate-limiting step is almost certainly the migration of phenyl that occurs in the initial eOH adduct (135). This is essentially the analogue for 1,2-diketones of the intramolecular Cannizzaro reaction on the 1,2-dialdehyde glyoxal, OHCCHO (p. 217). In the latter... 

The lactone 223 was isolated from 2-benzoyl-3-hydroxymethylquin-oxaline 1-oxide 221 on treatment with alkali and subsequent acidification, probably by intramolecular Cannizzaro reaction of 2-benzoyl-3-quinoxaline carboxyaldehyde (222), which in turn is obtained from 221 by a series of tautomeric shifts and 1,4-elimination.221... 

In a related Sequence of reactions, cyclization of 549 with POCl3 and then aqueous workup produced the carbinolamine 552. N-Methylation of 552 with methyl iodide followed by treatment with strong base resulted in an intramolecular Cannizzaro process to deliver the intermediate 553, which was converted to ( )-tazettine (397) by tosylation and base-induced elimination (215). 

In an intramolecular Cannizzaro the hydroxide-induced rearrangement of phthalaldehyde to o-hydroxymethylbenzoic acid (McDonald and Sibley, 1981), the pseudo first-order rate constant for appearance of product obeys equation (14). Phthalaldehyde exists as a cyclic hydrate [31] and the scheme... 

Intramolecular Cannizzaro reaction (a 3-Buten-2-one + (CH3CH2CH2)2CuLi... 

J. Rebek et al. synthesized novel dibenzoheptalene bislactones via a double intramolecular Cannizzaro reaction for condensation polymerization and remote catalysis studies. These bislactones are chiral, atropisomeric molecules. 

Russell, A. E., Miller, S. P., Morken, J. P. Efficient Lewis acid catalyzed intramolecular Cannizzaro reaction. J. Org. Chem. 2000, 65, 8381-8383. 

Bowden, K., Butt, A. M., Streater, M. Intramolecular catalysis. Part 8. The intramolecular Cannizzaro reaction of naphthalene-1,8-dicarbaldehyde and [a,a -2H ]naphthalene-1,8-dicarbaldehyde. J. Chem. Soc., Perkin Trans, 21992, 567-571. 

The prototype reaction is the conversion of glyoxal into glycolic acid (equation 2), and here the benzilic acid rearrangement mechanism coincides with that for an intramolecular Cannizzaro reaction. The reaction is observed with other purely aliphatic a-diketones such as f-butyl 2,3-dioxobutyrate and cyclohexane-1,2-dione (equations 3 and 4), but the scope is limited in the aliphatic series by competing (c.g. aldol) reactions. Suitably constructed heterocyclic systems also rearrange, and the conversion of alloxan (3) into alloxanic acid (4) was among the first of the benzilic acid rearrangements to be discovered (equation 5). ... 

An interesting reactivity is displayed by peri-dialdehyde 110. On boiling in water solution it undergoes an intramolecular Cannizzaro reaction to form the naphtho[l,8-c,d]pyranone derivative 198. It is noteworthy that the reaction does not require an addition of alkali, probably because the necessary basicity of the medium is provided by the substrate itself188. 

The released end-group forms an a-dicarbonyl structure which rearranges by an intramolecular, Cannizzaro type of reaction to yield saccharinates. Intramolecular reactions of the Cannizzaro type can occur not only with dialdehydes but also with a-ketoaldehydes and a-diketones ( benzilic acid rearrangement ) they can be exemplified by the base-catalyzed rearrangement of phenylglyoxal (VIII) [or of (2,4,6-trimethylphenyl)-glyoxal ] to the salt of mandelic acid (IX) (or of 2,4,6-trimethylmandelic acid). 

Successive elimination of an alkoxy group adjacent to an active hydrogen atom and intramolecular Cannizzaro reactions in alkaline solution, such as are found in saccharinate formation, are demonstrated by the conversion of 2-hydroxy-3-methoxy-3-phenylpropiophenone (X) to a salt of 2,3-diphenyllactic acid (XI). 

The latter results from an unusual intramolecular Cannizzaro-tjrpe reaction involving a transannular hydride transfer from C-20 to C-7. Oxidation of LXXVI followed by reduction gave the epimeric hydroxyl lactam LXXVII with the hydroxyl (p ax 1682 cm i) in the original configuration of ajaconine. The hydroxyl in LXXVI is thus trans to the i r-bridge and in LXXVII is cis thereto. Further evidence on this point is provided by the behavior of the methiodide (LXXVIII) of the azo-methine alcohol (LXVII). The product liberated from this salt by hot, methanolic alkali is a hydroxyl-free base (LXXIX, 10) and hence... 

A proposed mechanism, involving an intramolecular Cannizzaro reaction, is outlined below. The mechanism is not conclusive especially as the vicinal diols 87-90 have been reported to give the expected a-diketones under Swem conditions.50-53... 

GaUi M, Berrocal JA, Di Stefano S, et al. Highly efficient intramolecular Cannizzaro reaction between 1,3-distal formyl groups at the upper rim of a co)ie-caltx[4]arene. Org Biomol Chem. 2012 10 5109-5112. 

HaO, rt, lOh TMG= 1,1,3,3-tetramethylguanidine Example 4, Desymmetrization by intramolecular Cannizzaro reaction ... 

Potassium hydroxide Sterically controlled intramolecular Cannizzaro reaction ... 

Sterically hindered trisoxazoline (TOX) ligands, such as 165, were exploited in Cu(II)-catalyzed enantioselective intramolecular Cannizzaro reactions of aryl and alkyl glyoxals with alcohols (13JA16849). 

The reaction of trioses takes place in a similar manner (Figure 4.50). D-Glyceraldehyde or 1,3-dihydroxyacetone dehydration yields 1,2-diulose methylglyoxal (also known as pyruvic acid aldehyde or pyruvaldehyde) and the intramolecular Cannizzaro reaction of methylglyoxal yields lactic acid (racemate). 

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