Condensations by Sodium. XXXV. The Metalation and Cleavage of Ethers, Principally of Alkyl Phenyl Ethers,¹ by Amylsodium and Sodium

Abstract

Metalationand Cleavage of Ethers by Amylsodium 2973 V with m.p. 312-316°, [o]2Sd +12°, X™,01' 5.59 µ (note similar shift in the infrared lactone band of IV) and broad band at 5.88-5.92 µ; no color with alcoholic ferric chloride. Chromatography of the mother liquors furnished 41 mg. of the keto alcohol II, which was identified as its acetate.

CONDENSATIONS BY SODIUM. XXXVIII. THE METALATION OF tert-BUTYLBENZENE BY AMYLSODIUM AND THE EFFECTS OF ASSOCIATED SALTS1, 2

“…Already this idea of radicals has proven very useful, perhaps essential, for the interpretation of the pyrolysis of amylsodium (3), of the polymerization of butadiene by Alfin catalysts (4, 5), and of the cleavage of ethers (6). This idea may seem to violate chemical intuition but actually the underlying reasons for its adoption are in full accord with chemical tradition.…”

“…For instance, radicals are assumed to be present in many Grignard reactions and such intermediates should be more common with the thermally more unstable sodium reagents. Already this idea of radicals has proven very useful, perhaps essential, for the interpretation of the pyrolysis of amylsodium (3), of the polymerization of butadiene by Alfin catalysts (4, 5), and of the cleavage of ethers (6). With plausible assumptions the concept accords with the calculations of potential energy for a reagent of this class.…”

“…The theoretical amount of amylsodium was 0.45 instead of 0.30 mole, the temperature was 80°and the time was 2.5 hours. 6 Only those experiments which can be compared in the two series are averaged. The three other experiments are included in the table to show the products obtained under some special conditions.…”

Metalations With Organosodium Compounds

“…p-Methylanisole undergoes nuclear metalation ortho to the methoxyl group with n-amylsodium, although no yield is reported (70). o-Methylanisole, on the other hand, undergoes lateral metalation (42,43). These results, while not compelling because of the seemingly low yields, would seem to indicate that at least in the case of a methyl group, a side chain ortho to a methoxyl group is metalated more readily than one which is substituted para to that group.…”

“…also metalates isobutyl phenyl ether (80 per cent yield), n-butyl phenyl ether (76 per cent yield), ethyl phenyl ether (72 per cent yield), and isopropyl phenyl ether (50 per cent yield). In every case the ring is attacked ortho to the ether linkage (42).…”