Methoxybenzaldehyde, reduction

Anhalonine and Lophophorine. Spath and Gangl showed that each of these alkaloids contains a methylenedioxy group and that the quarternary iodide prepared from dZ-anhalonine is identical with lophophorine methiodide so that lophophorine must be N-methylanhalonine. Anhalonine was synthesised from 3 4-methylenedioxy-5-methoxybenzaldehyde by condensation with nitromethane, reduction of the product to the corresponding -ethylamine, the acetyl derivative (VII) of which, on treatment with phosphoric anhydride, condensed to 6-methoxy-7 8-methylenedioxy-l-methyl-3 4-dihydrofsoquinoline, m.p. 60-2°. This, on reduction, furnished the corresponding tetrahydrofsoquinoline, which proved to be anhalonine (VIII), and on conversion to the quaternary methiodide the latter was found to be lophophorine (IX) methiodide. The possible alternative, 8-methoxy-6 7-methylenedioxy-l 2-dimethyl-l 2 3 4-tetrahydrofsoquinoline, was prepared by Freund s method and the methiodide shown not to be identical with lophophorine methiodide. 

Aldol condensation of the methoxymethyl ether of m-methoxybenzaldehyde (83) with cyclohexanone affords the conjugated ketone 84. Michael addition of dimethyl amine leads to the ami noketone Reduction of the ketone... 

The synthesis of 3-H-oxazol-2-ones was described by Nam et al. [69]. The substituted benzoin 89 was formed from the coupling of 3,4,5-trimethoxy-benzaldehyde 18 with 3-nitro-4-methoxybenzaldehyde, Scheme 22. Reaction with PMB-isocyanate and subsequent cyclization gave the protected oxazolone derivative 90. The PMB group was removed by reflux in TFA and reduction of the nitro-group was performed using Zn to give the combretoxazolone-aniline 91. 

Methoxybenzaldehyde, 54, 42 p-Methoxybenzaldehyde, by reduction of p-methoxybenzo-nitrile with Raney nickel alloy, 51, 22... 

Ethoxy-3-methoxybenzyl alcohol 6, 2-(2-methoxyphenoxy)ethanol 8 and 1,3-dihydroxy-2-(2-methoxyphenoxy)propane 13 were formed from the B-0-4 dimer 1 in intact cultures, but not identified in the in vitro system. They axe probably formed secondeirily by reduction of initial cleavage products formed by the enzyme. In fact, this fungus reduces 4-ethoxy-3-methoxybenzaldehyde 7 and 2-benzyloxyacetaldehyde to the corresponding alcohols, il-ethoxy-3-methoxybenzyl alcohol 6 and a compound similar to 8, 2-benzyloxyethanol, respectively (23). 

Reduction ofp-methoxybenzaldehyde, typical procedure method A To lithium phenyltel-lurolate prepared from PhLi (2.1 M, 4 8 mL, 10 mmol) and Te (1.27 g, 10 mmol) in THF (30 mL) under Nj is added p-methoxybenzaldehyde (0.272 g, 2 mmol) at -78°C followed by TFA (0.77 mL, 10 mmol). The solution is stirred for a further 2 h, and allowed to warm at room temperature. H O (200 mL) is added and the product is extracted with ether. The extract is dried (Na2S04), evaporated and the residue separated by SiOj chromatography from the formed diphenyl ditellnride, giving p-methoxybenzyl alcohol (0.23 g (93%)). 

In the synthesis of analogues of calicheamicin 71 and esperamicin Ajb, Moutel and Prandi employed the glycosyla-tion of a nitrone with a trichloroacetimidate as a key step - /3-N-O glycosidic bond formation. Preparation of the nitrone begins with the alkylation of the known alcohol 69 <1992CC1494> with 1,4-dibromobutane in the presence of sodium hydride. Subsequent aminoalkylation, amine protection with 9-fluorenylmethoxycarbonyl (Fmoc), and reduction with NaBHsCN were followed by nitrone 70 formation with 4-methoxybenzaldehyde (Scheme 8) <2001J(P1)305>. 

Anastasio, C., B. C. Faust, and C. J. Rao, Aromatic Carbonyl Compounds as Aqueous-Phase Photochemical Sources of Hydrogen Peroxide in Acidic Sulfate Aerosols, Fogs, and Clouds. 1. Non-Phenolic Methoxybenzaldehydes and Methoxyacetophe-nones with Reductants (Phenols), Environ. Sci. Techno ., 31, 218-232 (1997). 

Quinazolines are of great interest in the pharmaceutical industry as protein tyrosine kinase inhibitors. Dener et al 8 described a synthesis starting from 2-methoxybenzaldehyde, Wang, or Rink resins. With the aldehyde resin reductive aminations were undertaken to yield polymer-bound secondary amines (Fig. 7). The latter were subjected to 2,4-dichloro-6,7-dimethoxyquinazoline to give the 4-amino-substituted derivatives. These were then allowed to react with primary or secondary amines at 135-140° in the presence of DBU in DMA. As a result of a detailed scope and limitation study, Dener et al,28 note that some bifunctional amines, such as piperazine, give to some extent dimeric derivatives. 

Arylcarbenes are formed from benzaldehyde and some of its derivatives if the Clemmensen reduction is performed using boron trifluoride or another Lewis acid instead of hydrochloric acid. If the reaction is carried out in the presence of an alkene, which is often used as solvent, addition to the C-C double bond takes place and cyclopropane formation results in low to fair yields. The arylcyclopropanes are always formed as mixtures of stereoisomers and, in all cases but two, the endo-isomcr is significantly predominant. Thus, when a mixture of 4-methoxybenzaldehyde, boron trifluoride-diethyl ether complex and a considerable excess of cyclohexene was allowed to react with amalgamated zinc, 7-(4-methoxyphenyl)bicy-clo[4.1.0]heptane (1) was obtained in 60% yield. 

ALDEHYDES FROM ACID CHLORIDES BY MODIFIED ROSEN-MUND REDUCTION 3,4,S-TRI-METHOXYBENZALDEHYDE,... 

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