2- Naphthoyl chloride reduction

Of the tetrahydronaphthalene derivatives (III-VI) required for this work, all of the monosubstituted compounds (III and IV) are known. However, IVa and IV6 were prepared from 5,6,7,8-tetra-hydro-l-naphthoyl chloride by Rosenmund reduction and by reaction with dimethyleadmium, respectively, rather th n by previously published methods. 

This reagent has also been converted to the dithioacid with carbon disulfide and this acid converted to 3-naphthaldehyde by way of its semicarbazone. (3-Naphthaldehyde has been made by the reduction of /3-naphthonitrile according to Stephen and by the reduction of 3-naphthoyl chloride according to Rosenmund." The procedure described is based on the method developed by Rosenmund and applied by him and others to... 

The rest of the synthesis is described only briefly in the original communication (ref. 59) and no yields are quoted. Coupling of the isoquinoline with naphthoyl chloride 60 gives the ester 100 which undergoes intramolecular Pd(II) catalysed coupling to give the lactone 101. Reduction followed by deoxygenation and then provided (+)-ancistrocline (3). 

The acyl-alkyl rearrangement becomes a main path with some acyl halides. Actually, formation of the decarbonylation product has been reported in several cases as an abnormal reaction of the Rosenmund reduction. Sterically hindered acyl halides such as diphenylacetyl and triphenylacetyl chlorides and naphthoyl chloride undergo decarbonylation in attempted Rosenmund reduction (Scheme... 

Rosenmund Reaction. A catalyst poison prepared from quinoline and sulfur is useful for controlling the reaction of p-naphthoyl chloride (19) with hydrogen gas and palladium on barium sulfate catalyst. If control of the reaction is not maintained by catalyst poisoning to reduce activity, further reduction beyond the desired /3-naphthaldehyde product (20) is often observed (eq 13). ... 

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