7- Methoxy-1 -tetralone mixture

Synthesis (Freed and Potoski (American Home), 1971 Freed, 1973 Kleemann et al., 1999,) Dezocine is prepared through the following sequence The condensation of 1-methyl-7-methoxy-2-tetralone with 1,5-di-bromopentane by means of NaH or potassium tertbutylate affords 1 -(5-bromopentyl)-1 -methyl-7-methoxy-2-tetralone this product is cyclized with NaH to give 5-methyl-3-methoxy-5,6,7,8,9,10,11,12-octahydro-5,11 -methano-benzocyclodecen-13-one i. The ketone i, by reaction with hydroxylamine hydrochloride in pyridine, is converted into its oxime ii, which is reduced with H2 over Raney Ni to a mixture of isomeric amines which were separated by crystallization of the HCI salts giving 5-a-methyl-3-methoxy-5,6,7,8,9,11 a, 12-octahydro-5,11 -methanobenzo-cyclodecen-13p-amine, which is finally cleaved with concentrated HBr. 

An alternative cyclization via a 1-tetralone intermediate has been achieved by Inoue and May,(15) Scheme 4.5. The key intermediate (41) was prepared from frmercuric acetate gave a mixture of the three benzomorphans (42, 49% 43, 13% 44, 5%). Hydrogenation of 42 afforded 3,lla-dimethyl-8-methoxybenzomorphan (45). 

The structure and absolute stereochemistry of hinesol (282) has now been firmly established by an unequivocal synthesis which involved the tricyclic dienone (329) prepared from 6-methoxy-l-tetralone. Treatment of the dienone with lithium dimethylcopper gave a mixture of syn and anti enones (330). By a series of stereoselective reactions this compound was converted to the diol (331) whose mono-mesylate underwent a base-induced cleavage to give the spiro[4,5]-ketone (332). Elaboration of this ketone to hinesol was accomplished along... 

Chang, H., and D. G. Morrell. 1985. Solubilities of methoxy-l-tetralone and methyl nitrobenzoate isomers and their mixture in supercritical carbon dioxide. J. Chem. Eng. Data 30 74. 

A mixture of 2-formyl-7-methoxy-l-tetralone, methyl thiotosylate, freshly fused K-acetate, and abs. ethanol refluxed 4 hrs. under Ng 2-methylthio-7-methoxy-... 

The total synthesis of derivatives of 19-norpregnane from the bicyclic ketone (134) has been developed by Nagata et al. [28, 247-249] (Scheme 13). The addition of ring C to 6-methoxy-2-tetralone (134) by Robinson s method gave the tricyclic ketone (135), which is a mixture of the and... 

The first stage of the synthesis, the preparation of the unsaturated cyclic ketone (140) is illustrated in Scheme 94. Here the starting material is 5-methoxy-2-tetralone (51), which was obtained in two stages from 2, 5-dihydroxynaphthalene with an over-all yield of 73% (Chapter HI, Scheme 56). Condensation of the tetralone (51) with l-diethylamino-3-pentanone methio-dide led to a mixture of the A - and A -tricyclic ketones (138). The next stage, the formation of ring A, can be carried out both with methyl vinyl ketone (yield 75%) and with l-diethylamino-3-butanone methiodide (yield 64%). The isolation of the tricyclic ketones (138) was not necessary, and by successively condensing the tetralone (51) with the diethylaminopen-tanone methiodide and methyl vinyl ketone it was possible to obtain the tetracyclic product (140) with an over-all yield of 34% [915, 916]. 

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