O-Tetralone

Tetralone is readily mono- or di-alkylated at the 1-position to the exclusion of O-alky lation with a range of alkylating agents under liquiddiquid two-phase conditions without an added solvent [24], Similarly, it has been reported that anthrone undergoes mono- and di-C-alky lation at the 10-position with propargyl and allyl halides to the almost complete exclusion of O-alkylation [25]. It has been claimed that methyl-ation yields 9-methoxyanthracene [26],... 

Autoxidation may in some cases be of preparative use thus reference has already been made to the large-scale production of phenol+ acetone by the acid-catalysed rearrangement of the hydroperoxide from 2-phenylpropane (cumene, p. 128). Another example involves the hydroperoxide (94) obtained by the air oxidation at 70° of tetrahydro-naphthalene (tetralin) the action of base then yields the ketone (a-tetralone, 95), and reductive fission of the O—O linkage the alcohol (a-tetralol, 96) ... 

Schmidt reaction on /3-tetralone yields a 2 1 mixture of the 2-benzazepin-3-one and 3-benzazepin-2-one, whereas the l-benzyl-2-tetralone (198 X = O) yields only l-benzyl-2-benzazepin-3-one (76HCA2059). 

Oxidation of tetraiones.3 The tetralone 1 is oxidized directly to the o-naphtho-quinonc 2 by selenium dioxide in acetic acid. 

The iV-aminopyrrole - benzene ring methodology has been applied to a synthesis of the 9,10-dihydrophenanthrene juncusol (218) (81TL1775). Condensation of the tetralone (213) with pyrrolidine and reaction of the enamine with ethyl 3-methoxycarbonylazo-2-butenoate gave pyrrole (214). Diels-Alder reaction of (214) with methyl propiolate produced a 3 1 mixture of (215) and its isomer in 70% yield. Pure (215) was reduced selectively with DIBAL to the alcohol, reoxidized to aldehyde, and then treated with MCPBA to generate formate (216). Saponification to the phenol followed by O-methylation and lithium aluminum hydride reduction of the hindered ester afforded (217), an intermediate which had been converted previously to juncusol (Scheme 46). 

It has been suggested that the benzo[c]furan (245) is formed from the tetralone derivative (244) on treatment with o-phthalaldehyde in acetic acid-sulfuric acid (71JCS(C)2175). 

O. 5 mL/min flow rate was found suitable for this study. It is interesting to note that there was no improvement in resolution when the flow rate was decreased below 0.5 mL/min. In another study, Aboul-Enein and Ali [94] optimized the chiral resolution of certain tetralone derivatives (Fig. 18) on a Chiralpak AD-RH CSP. The results of these findings are given in Table 6, where kx and k2 are, respectively, negative and positive retention factors. Similarly, the flow rates were varied from 0.5 mL/min to 2.0 mL/min. It was observed that the 0.5 mL/min flow rate was suitable for the chiral resolution of most of the derivatives. All the tetralone derivatives studied resolved completely at 0.5 mL/min when water-acetonitrile-triethylamine (50 50 0.03, v/v/v) served as the mobile phase. However, partial resolution of tetralone derivative IV was observed at 0.5 mL/min when water-acetonitrile-acetic acid (60 40 0.03, v/v/v) was the mobile phase. This study shows that the optimization of chiral resolution can be achieved by adjusting the flow rate. 

The excellent method for cyclizing o-benzylbenzoic acids to anthranol acetates, by heating the acid in- a mixture of acetic acid, and anhydride with zinc chloride as a catalyst,228 has been used also in the preparation of cyclic ketones of the tetralone type. In this way 7-3-acenaphthylbuty-ric acid has been cyclized in 78% yield 224 Y-2-phenanthrylbutyric acid48 and the 9,10-dihydro derivative97 in 51% and 59% yields respectively and a,j8-dimethyl-Y-2-naphthylbutyric acid in 90% yield.186... 

The synthesis of methyl ( )-o-methy lpi si ferate (5) developed by Pal and Mukeijee possesses some interesting features (i) the smooth conversion of tetralone (42) to diazomethyl ketone (48), (ii) aryl... 

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