Friedel-Crafts acylation reactions reduction

Diels-Alder reaction, 493 El reaction, 391-392 ElcB reaction, 393 E2 reaction, 386 Edman degradation, 1032 electrophilic addition reaction, 147-148. 188-189 electrophilic aromatic substitution, 548-549 enamine formation, 713 enol formation, 843-844 ester hydrolysis, 809-811 ester reduction, 812 FAD reactions. 1134-1135 fat catabolism, 1133-1136 fat hydrolysis, 1130-1132 Fischer esterification reaction, 796 Friedel-Crafts acylation reaction, 557-558... 

The orientation is right attack is para to one of the methoxy groups and ortho to the methyl. The substrate for the Friedel-Crafts acylation reaction, 3,4-dimethoxytoluene, is prepared from compound A by a Clemmensen or Wolff-Kishner reduction. Compound A cannot be acylated directly because it bears a strongly deactivating —CH substituent. 

The pentyl group must be put on by a Friedel-Crafts acylation reaction followed by a reduction to avoid rearrangement. The bromine must be added at the acyl stage to get meta orientation. 

Reductions. In contrast to hydrosilylation reactions catalyzed by metal chlorides, aldehydes and ketones are rapidly reduced at rt by Triethylsilane and BF3-OEt2, primarily to symmetrical ethers and borate esters, respectively. Aryl ketones like acetophenone and benzophenone are converted to ethylbenzene and diphenyl-methane, respectively. Friedel-Crafts acylation-silane reduction reactions can also occur in one step using these reagents thus Benzoyl Chloride reacts with benzene, triethylsilane, and BF3-OEt2 to give diphenyhnethane in 30% yield. ... 

The history of the chemistry of l,12-dimethylbenzo[c]phenanthrene (2) resembles that of 4,5-dimethylphenanthrene (1). The first symthesis of 2 was reported by Newman and Wolf in 1952 [9]. The synthetic sequence included preparation of diacid 67 for the Friedel-Crafts acylation reactions to form diketone 68 (Scheme 15). Reduction followed by dehydration and dehydrogenation then produced 2. 

As shown in Scheme 1, the synthesis of fert-butyl phenalenyl radical 10 started from 2,7-di-ferf-butylnaphthalene in ten steps. Bromination of 2,1-di-tert-butylnaphthalene gave 6 in high yield, which was converted into aldehyde by lithiation followed by reaction with DMF. Successive Reformatsky reaction afforded ester 7, which upon reduction, hydrolysis, and Friedel-Crafts acylation reaction gave the phenalanone 8. The key intermediate 9 was then obtained as pale yellow crystals by reduction of 8 and subsequent dehydration. Oxidation of 9 with p-chloranil in degassed toluene led to a blue neutral radical solution while similar treatment in hexane gave deep blue needles. This crystal showed high stability in the absence of air, while changing into phenalanone derivatives and other byproducts in 1 week in air. 

Another category of reductions involves aryl ketones. The Friedel-Crafts acylation reaction reacts benzene with an acid chloride such as butanoyl chloride (49) to give an aryl ketone, 50. Complete removal of the oxygen from this ketone constitutes a method to make straight-chain arenes, which cannot be prepared via Friedel-Crafts alkylation (see Section 21.3.2). At least two classical methods are used to accomplish this reaction, which is formally a reduction. If 50 is treated with zinc metal in HCl, the product is 1-phenylbutane, 105. This acidic reduction involves a mineral acid such as HCl and an active metal, and it is called the Clemmensen reduction. 

A straight-chain alkyl group can be placed on a benzene ring via a Friedel-Crafts acylation reaction, followed by reduction of the carbonyl group by catalytic hydrogenation, a Clemmensen reduction, or a Wolff-Kishner reduction. 

The acid 2.8 is used to provide the acid chloride which gives a route to dimethylene linked-compounds by Friedel-Crafts acylation and reduction of the product ketone [34] and the alcohol 2.7 is used for the methyl-eneoxy-linked systems [36] by a direct DEAD reaction to a phenol [37] or by conversion into an alkyl halide or tosylate and reaction with a phenolate anion. 

Acetophenone is readily available (and if it were not, it s simple to make by a Friedel-Crafts acylation reaction), and it is readily nitrated to weta-nitroacetophenone. For the reduction of the ketone to a hydrocarbon. I ve chosen a new reaction, the Wolff-Kishner reduction, which we... 

Reaction of the potassium salt of salicylaldehyde with chlo-roacetone affords first the corresponding phenolic ether aldol cyclization of the aldehyde with the ketonic side chain affords the benzofuran (1). Reduction of the carbonyl group by means of the Wolf-Kischner reaction affords 2-ethyl-benzofuran. Friedel-Crafts acylation with anisoyl chloride proceeds on the remaining unsubstituted position on the furan ring (2). The methyl ether is then cleaved by means of pyridine hydrochloride (3). lodina-tion of the phenol is accomplished by means of an alkaline solution of iodine and potassium iodide. There is thus obtained benziodarone (4)... 

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