4- Methoxy- benzyl methyl ketone

M p-methoxy-benzyl-methyl ketone (l-p-methoxy-phenyl-2-propanone) (or analog), 20 g NH Cl, 225 ml methanol saturated with NHj, 25 ml NH OH and shake with 1-3 atmospheres Hj until uptake ceases. Filter, wash precipitate with methanol or acidify with HCl and dry, evaporate in vacuum to get p-methoxy-amphetamine or analog. 

In contrast to that of benzyl methyl ketone, deuteriation (or dedeuteriation) of methoxyacetone occurs preferentially at the methyl group in acidic conditions (Bothner-By and Sun, 1967 Hine et al., 1967a Chevallier et al., 1969). The peculiarity of this result has been emphasised by Hine. Indeed, since the methoxy group is expected to stabilise the double bond, enol [501 must be more stable than enol [511. This conclusion is supported by the ab initio calculations of Hehre and Lathan (1972). 

The stereospecific C-alkylation of a range of benzylic ketones, such as tetralones, 2-phenylcyclohexanones and cycloheptanones, and 2-phenyl-y-lactones, has also been described [8]. For example, Af-(4-trifiuoromethylbenzyl)cinchonidinium bromide catalyses the reaction of 1,5-dibromopentane with 7-methoxy-l-methyl-2-tetralone to yield the (R)-l-(5-bromopentyl) derivative (75% yield with 60% ee). 

Alkyl aryl ketimines were reduced with up to 99% ee (Scheme 8) [24]. The high enantioselectivity was not affected by the E Z ratio of the imines. For example, a 1.8 1 E Z mixture of the N-propylimine of 4 -methoxy-3-methyIbuty-rophenone was converted to the desired product in 97% optical yield. Hydrosilylation of the N-propylimine of cyclohexyl methyl ketone with a substrate to Ti molar ratio of 2,000 1 was completed to give the product in 98% ee [24]. N-Benzylimine of 2-octanone, a simple aliphatic ketimine, was reduced with 69% optical yield. The reduction of W-benzyl-l-indanimine gave the corresponding amine in 92% ee (Scheme 9) [24]. 

Using (2) as catalyst provided the (R) enantiomer in 99% yield, 78% ee. The key introduction of asynunetry during the synthesis of (+)-podocarp-8(14)-en-13-one was the phase-transfer-catalyzed Robinson annulation of 6-methoxy-l-methyl-2-tetralone with ethyl vinyl ketone. The authors carried out a comparative study of the A/-(4-trifluoromethyl)benzyl derivatives of cinchonine, cinchonidine, dihydrocinchonine, and dihydrocinchonidine and found that (5) produced the highest ee of the desired (S) enantiomer at —45 °C using toluene and 60% aq KOH (eq 10). ... 

Also obtained by partial methylation of 2,4-dihydroxy-6-methoxy-3-methylphe-nyl 4-methoxy-benzyl ketone with methyl iodide in the presence of potassium carbonate in boiling acetone [5495] for 2 h (96%) [5538],... 

Preussomerin I 697 and ( )-preussomerin G 698 were obtained from 620 with a five- and six-steps sequence in 15% and 12% overall yield, respectively, through modifications of substituents of the dioxocin ring. Thus, attack of lithium methoxide from the less hindered face of the enone 620, followed by protection of the phenolic oxygen as its methyl ether provided the methoxy adduct 692. The ketone 693 was obtained through a benzylic bromination-solvolysis-oxidation protocol, which required only a single purification. The C(2)-C(3) olefin was introduced by selective silylation of the C-l carbonyl of diketone 693 and oxidation of the silyl enol ether with Pd(OAc)2. Enone... 

Photocleavage of benzyl-S bonds appears to proceed neither by an electron transfer pathway nor with participation of an exciplex. A meta effect seems to operate in these reactions as evidenced by the influence of 3-methoxy and of 3-cyano substituents on the efficiency of the cleavage process. Photolysis of 1,2-bis(phenoxymethyl)-, l,2-bis(phenylthiomethyl)-, and l,2-bis(phenylseleno-methyl)benzene induces a two-photon process to give o-quinonedimethane, which in the presence of dienophiles undergoes a cycloaddition reaction, and 4,8,10-trithiadibenzo[cd,ij]azulene 8-oxides gives the corresponding aldehydes and ketones together with 4,8,9-trithiacyclopenta[def]phenanthrene. The two... 

The synthesis of the 10-methoxytetracyclic ketone 353 (Scheme 26) started from the readily available 3-methyl-5-methoxyindole 355, which after Boc protection, was brominated, and then condensed with the anion of the Schollkopf auxiliary 356 (from l-valine). Removal of the Boc-protecting group, followed in succession by A -methylation and hydrolysis, gave the required A -methyl-5-methoxy-D-tryptophan ethyl ester 357, which was then transformed into the key 10-methoxytetracyclic ketone 353, via N-benzylation, Pictet-Spengler condensation, and Dieckmann cyclization. Subsequent N-alkylation by the vinyl iodide 358 followed by Pd-catalyzed (enolate-driven)... 

Obtained by partial methylation of 2,4-dihy-droxy-6-methoxy-5-prenylphenyl benzyl ketone with dimethyl sulfate in the presence of potassium carbonate in refluxing acetone for 4 h [5352], m.p. 80-81° [5352] H NMR [5352] TLC [5352]. 

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