Propionaldehyde 3-methoxy

Synthesis of racemic naproxene Friedel-Crafts acylation (aluminum chloride - nitrobenzene) of p-naphthol methyl ether affords 2-acetyl-6-methoxy naphthalene, which, when treated with either dimethyl sulfonium or dimethylsulfoxonium methylide, gives 2-(6-methoxynaphthalen-2-yl)propylene oxide. Treatment of the latter with boron trifluoride etherate in tetrahydrofuran gives 2-(6-methoxynaphthalen-2-yl)propionaldehyde, which is oxidized using Jones reagent (4 M chromic acid) to yield the racemic 2-(6-methoxynaphthalen-2-yl)propionic acid. 

The PPA-promoted cyclizations of (phenylthio)acetaldehyde dimethyl acetal and a-(phenylthio)propionaldehyde diethyl acetal yield benzo[6]thiophene together with 3-methoxy-2,3-dihydrobenzo-[6]thiophene, and a mixture of 2- and 3-methylbenzo[6]thiophene, respectively.296 Mechanisms have been proposed to account for these results. 

Yamamoto et al. ° have examined the addition of allyl organometallic reagents to a-alkoxyaldimines (40) derived from (S)-2-methoxy(methoxy)propionaldehyde and (/ )- and (S)-l-phenylethylamine (equation 10). The results are summarized in Table 10. Chelation control with allyl-AlEtaMgCl, -MgCTl and -ZnBr (entries 1-3, Table 10) and nonchelation (Cram) control with allyl-Ti(Pi O)3, -B(OMe)2 and -9-BBN (entries 4-6, Table 10) parallels that observed in the allyl metal-a-alkoxyaldimine additions (involving aldimines that lack a chiral nitrogen substituent) shown in Table 6. The chirality of the a-alkoxy... 

Materials. Terephthaldicarboxaldehyde (Aldrich), diethyl bis(hydroxymethyl) malonate (Aldrich), p-toluenesulfonic acid (Aldrich), potassium hydroxide (85 wt%, Fisher), pyridine (Fisher), glutaric dialdehyde (50wt% aqueous solution, Aldrich), ethylene glycol divinyl ether (Aldrich), ethyl glycolate (Aldrich), isophthalic dicarboxaldehyde (Lancaster), propionaldehyde (Eastman Chemical), isovaleraldehyde (Aldrich), 2-ethyl-2-oxazoline (Acros), ammonia (7M in methanol, Acros), l-methoxy-4-(methylthio)benzene (Aldrich), silver... 

Methoxy.zimtaldehyd.hydrazon 8 II150. Propionaldehyd-benzoylbydiazon 9, 321, 1129. 

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