Acetyl chloride structure

The formation of acyl halide-Lewis acid complexes have been observed by several methods. For example, both 1 1 and 1 2 complexes of acetyl chloride, with AICI3 can be observed by NMR spectroscopy. The existence of acylium ions has been demonstrated by X-ray diffraction studies on crystalline salts. For example, crystal structure determinations have been reported for /i-methylphenylacylium and acetylium ions as SbFg salts. There is also a good deal of evidence from NMR measurements which demonstrates that acylium ions can exist in nonnucleophilic solvents. " The positive charge on acylium ions is delocalized onto the oxygen atom. This delocalization is demonstrated in particular by the short O—C bond lengths in acylium ions, which imply a major contribution from the structure having a triple bond ... 

Friedel-Crafts acylation of the individual isomers of xylene with acetyl chloride and aluminum chloride yields a single product, different for each xylene isomer, in high yield in each case. Write the structures of the products of acetylation of o-, m-, and p-xylene. 

Figure 20.1 shows the structures of various derivatives of acetic acid (acetyl chloride, acetic anhydride, ethyl thioacetate, ethyl acetate and acetamide) arranged in order... 

A variant on this structure, dioxyline, has much the same activity as the natural product but shows a better therapeutic ratio. Reduction of the oxime (113) from 3,4-dimethoxyphenyl-acetone (112) affords the veratrylamine homolog bearing a methyl group on the amine carbon atom (114). Acylation of this with 4-ethoxy-3-methoxyphenyl acetyl chloride gives the corresponding amide (115). Cyclization by means of phosphorus oxychloride followed by dehydrogenation over palladium yields dioxyline (116). ... 

Though it could be argued that a planar structure analogous to 11 for acetyl chloride would be disfavored by steric crowding between the chlorines and the methyl group, this was not found to... 

Imidates 60 were prepared in two steps by first reacting nitrile derivatives with various alcohols. The condensation of the obtained iminoester with appropriate acetyl chloride resulted in the formation of the title compounds 60a-c (Scheme 12). The structures of the products 60 were elucidated by means of spectroscopic analysis. 

The reactions of betaines 20a, n with acetyl chloride are unusual.84,97 The structure and composition of the products formed depend on the molar ratio of reactants. At equimolar amounts of the reactants in THF, the cyclic compound 54 is formed in 96-98% yield (Scheme 26). 

Besides direct solid phase fixation, the functional OH-group of 49 may be used for further transformations. Esterification with acetyl chloride at the OH-linker (Scheme 27) leads to 50, providing a heteroscorpionate ligand with the protected OH-linker. An intramolecular hydrogen bridge is found in the X-ray structure [d(01-N21) = 2.478 (3) A] between the carboxylic acid and the pyrazole nitrogen (Fig. 32b). 

It has been demonstrated that organotin-mediated multiple carbohydrate esterifications can be controlled by the acytaring reagent and the solvent polarity. When acetyl chloride is used, the reactions are under thermodynamic control, whereas when acetic anhydride is employed, kinetic control takes place. Very good selectivity can furthermore be obtained in more polar solvents. These results can be used in the efficient preparation of prototype carbohydrate structures. 

Interestingly, treating (>/4-cyclooctatetraene)Fe(CO)3 with acetyl chloride under Friedel-Crafts reaction conditions yielded unexpectedly222-223 the (>/2,>/3-8-e.x0-acetyl bicy-clo[3.2.1]octadienylium)Fe(CO)3 cation complex, presumably by rearrangement of the intermediate bicyclo[5.1.0]octadienylium isomer (Scheme 8). The structure of the rearranged cation was confirmed from the X-ray crystal structure and from the typical 1,3-cr.ji-allylic products obtained upon nucleophilic reaction with LiAlD4 and NaCN. The nucleophilic reaction of the more bulky iodide occurs, however, on the metal. 

Kamiya et al. found that 207 (R = H, R = OH) underwent annelation rearrangement in acetyl chloride/DMF to 237. The structure of this latter compound, as well as derivatives of 207 [i.e., R = R = H R = Ac, R = OAc R = Ac, R = OH], were confirmed by X-ray diffraction analysis and were thus incompatible with the earlier benzodiazepine structures assigned to these compounds (73CPB1520) (see Section IV,A,2). 

The imine moiety of l//-l,4-bcnzodiazepin-2-(3//)ones reacts regio- and stereospecifically with a range of functionalized ketenes to afford substituted, fused /3-lactam [2+2] cycloaddition adducts (Scheme 21) <2004EJ0535>. The use of [4-(3 )-2-oxo-4-phenyloxazolidin-3-yl]acetyl chloride, as a homochiral ketene precursor, afforded a single product, the structure of which was established by X-ray crystallography, while the (4,y,5fJ)-diphenyl analogue provided a 1.8 1 mixture of chromatographically separable diastereomers. 

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