O-methylbenzaldehyde

The cycloaddition of photoenol of o-methylbenzaldehyde 66 with 5-alkyli-dene-l,3-dioxane-4,6-dione derivatives 67 is an example of a photo-induced Diels Alder reaction in which one component, the diene in this case, is generated by irradiation [48]. The yields of some cycloadducts 68, generated by photo-irradiation of a benzene solution of 66 and 67 at room temperature, are reported in Table 4.14. The first step of the reaction is the formation of (E)-enol 69 and (Z)-enol 70 (Equation 4.7) by an intramolecular hydrogen abstraction of 66 followed by a stereo- and regioselective cycloaddition with... 

Chemical/Physical. Under atmospheric conditions, the gas-phase reaction of o-xylene with OH radicals and nitrogen oxides resulted in the formation of o-tolualdehyde, o-methylbenzyl nitrate, nitro-o-xylenes, 2,3-and 3,4-dimethylphenol (Atkinson, 1990). Kanno et al. (1982) studied the aqueous reaction of o-xylene and other aromatic hydrocarbons (benzene, toluene, w and p-xylene, and naphthalene) with hypochlorous acid in the presence of ammonium ion. They reported that the aromatic ring was not chlorinated as expected but was cleaved by chloramine forming cyanogen chloride. The amount of cyanogen chloride formed increased at lower pHs (Kanno et al., 1982). In the gas phase, o-xylene reacted with nitrate radicals in purified air forming the following products 5-nitro-2-methyltoluene and 6-nitro-2-methyltoluene, o-methylbenzaldehyde, and an aryl nitrate (Chiodini et ah, 1993). 

Irradiation of o-methylbenzaldehyde in the presence of maleic anhydride give G. The same compound is obtained when H is heated with maleic anhydride. Both reactions give only the stereoisomer shown. Formulate a mechanism. 

In a manner similar to the Sml2-mediated homocoupling of enantiomerically pure (o-methylbenzaldehyde)-Cr(CO)3, the coupling reaction of the [methyl(o-tolylmethylene)amine]Cr(CO)3 complex 17 with SmE gives only ry -diamine 18 along with the reduced amine 19 (Equation (63)). ... 

Photoadditions of bis-(p-sulphonyl)selenide and alkaneselenosulphonates and of thiophenol to alkenes have also been reported. The photoreaction of sulphur dioxide with cis-but-2-ene has been described, and the a-oxygenated benzothiophene dioxides (235) have been prepared in good yield by irradiation of the o-methylbenzaldehydes (236) in the presence of sulphur dioxide as shown in Scheme 14. ... 

The alkylation at the ortho carbon is possible by the reaction of chelate complexes with Grignard reagents, organolithium reagents in the presence of PPhs, or alkyl halides. o-Methylbenzaldehyde was prepared via the formation of a Schiff base complex 423 and its reaction with MeLi [178]. The ortho alkylation is possible even with alkyl halides. Treatment of acetanilide (424) with 3 equivalents of... 

CAS 529-20-4 EINECS/ELINCS 208-452-2 Synonyms 2-Formyltoluene 2-Methylbenzaldehyde o-Methylbenzaldehyde o-Tolualdehyde o-Toluic aldehyde o-Toluylaldehyde Classification Aromatic aldehyde Empirical CaHaO Formula CH3C6H4CHO... 

Benzocyclpbutenes. When benzocyclobutenol is heated, it is converted into o-methylbenzaldehyde, If the reaction is done in the presence of a dienophile such as dimethyl acetylenedicarboxylate, an adduct (350) is formed. These observations suggest that the hydroxy-o-quinone dimethide (349) is the initial... 

Unlike in the case of photoenols, whose Z-conformations decay very rapidly back to the ketones by tunneling, exploratory quantum chemical calculations showed that this problem was not of concern in radical cations, as the enolization of o-alkyl phenyl ketone radical cations is exothermic by at least lOkcalmol", because the ionization energies of the o-quinoid enols are much lower than those of the aromatic ketones, as illustrated in Figure 4.1 for the example of o-methylbenzaldehyde. 

Figure 4.1 Relative energies of the keto and enoi form of o-methylbenzaldehyde and their radical cations, from B3LYP/6-31G caicuiations.

---