Mesitaldehyde

P-Naphthol-a-aldehyde (p-hydroxy-a naphthaldehyde). Proceed as for p-resorcylaldehyde except that 20 g. of p-naphthol replaces the resor-dnol. Recrystallise the crude product (20 g.) from water with the addition of a little decolourising carbon the pure aldehyde has m.p. 80-81°. 

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The reaction mixture is poured into a separatory funnel containing about 0 S kg. of crushed ice and is shaken thoroughly. The organic layer is separated, and the aqueous solution is extracted with two SO-ml. portions of methylene chloride. The combined organic solution is washed three times with 75-ml. portions of water A crystal of hydroquinone is added to the methylene chloride solution (Note 1) which is then dried over anhydrous sodium sulfate. After evaporation of the solvent, the residue is distilled to give the crude product, b p. 68-74° (0.9 mm.). After redistillation there is obtained 60-66 g. (81-89%) of mesitaldehyde b.p. 113-115° (11 mm.), 20d 1.5538. 

Mesitaldehyde may be prepared from mesitylmagnesium bromide by the reaction with orthoformate esters3 or ethoxy-methyleneaniline 3 from acetylmesitylene by oxidation with potassium permanganate,4 from mesitoyl chloride by reduction,5 from mesityllithium by the reaction with iron pentacarbonyl and from mesitylene by treatment with formyl fluoride and boron trifluoride,7 by treatment with carbon monoxide, hydrogen chloride, and aluminum chloride,8 or by various applications of the Gatterman synthesis.9-11... 

The preparation of mesitaldehyde is an example of a generally applicable method for the preparation of aromatic aldehydes by treatment of aromatic compounds with dichloromethyl methyl... 

Determination of the solvent and substrate isotope effects in the deacylation of mesitaldehyde yielded the coefficients in Table 222652. The substrate isotope... 

Meanwhile, the described methods of fractionation came into general synthetic practice. For instance, mesitaldehyde-3,5-d2 was prepared by reaction of mesitaldehyde with D2SO4 following up to the arene protio-deuterio exchange method (Jiao et al. 2007). 

Mercury benzamide, 797 Mercury-sealed stirrers, 66-69, 220 Mesitaldehyde, 690, 701 Mesityl oxide, 353 Metaldehyde, 319 Metanilic acid, 586, 589 Methiodides, 660 Metho-p-toluenesulphonates, 660 p-Methoxyacetophenone, 733 p-Methoxybenzaldehyde, 690, 703 4-Methoxybenzoin, 708, 714 p-Methoxycinnamic acid, 719 p-Methoxyphenylacetic acid, 904, 905, 924, 925... 

Selective reduction of aldehydes.2 This reduction can be effected with formic acid (1.25 equiv.) and triethylamine (1 equiv.) and a catalytic amount of RuC12[P(C6H5)3]3 at 25° in THF. Under these conditions nitro, keto, ester, and t-amide groups are not reduced. The reduction of aldehydes, however, is sensitive to steric hindrance. Thus mesitaldehyde is reduced very slowly. 

Figure 10.2 illustrates selected examples of these epoxide products. Aromatic and heteroaromatic aldehydes proved to be excellent substrates, regardless of steric or electronic effects, with the exception of pyridine carboxaldehydes. Yields of aliphatic and a,/ -unsaturated aldehydes were more varied, though the enantio-selectivities were always excellent. The scope of tosylhydrazone salts that could be reacted with benzaldehyde was also tested (Fig. 10.3) [29]. Electron-rich aromatic tosylhydrazones gave epoxides in excellent selectivity and good yield, except for the mesitaldehyde-derived hydrazone. Heteroaromatic, electron-poor aromatic and a,/ -unsaturated-derived hydrazones gave more varied results, and some substrates were not compatible with the catalytic conditions described. The use of stoichiometric amounts of preformed sulfonium salt derived from 4 has been shown to be suitable for a wider range of substrates, including those that are incompatible with the catalytic cycle, and the sulfide can be recovered quantitatively afterwards [31]. Overall, the demonstrated scope of this in situ protocol is wider than that of the alkylation/deprotonation protocol, and the extensive substrate...

MALONIC ACID, ETIIYLHYDROXY-, DIETHYL ESTER, BENZOATE, 46, 37 Mesitaldehyde, 47,1 Mesitylene, condensation with dichloro-methyl methyl ether, 47, 1 Methallyl chloride in alkylation of 2,4-pentanedione with potassium carbonate, 47, 87... 

The benzaldehyde addition which was most intensively investigated gave a 88 12 mixture of endo and exo diastereoisomers 118. Thus, the thermodynamically less stable stereoisomers (>1.5kcal/mol, from ab initio calculation) were formed preferentially. To further enlarge the phenyl substituent, ortho-tolyl and mesitaldehyde as well as... 

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