A1 -Octalin

To add another complication recently, (R)-(—)-10-methyl-A1(-9)-octalin (7) has been prepared and its hydrogenation studied over Pt, Pd, and Rh catalysts.91 Like the apopinenes and the (R)-(—)-4-methylcyclohexene, this R enantiomer may undergo double bond migration to its 5 enantiomer, which... 

The synthesis of ( )-D-homotestosterone and ( )-progesterone has been accomplished via a now classical procedure involving the use of an isoxazole as an annelating agent (67JA5464). The enolate (424), prepared from 10-methyl-A1,9-octalin-2,5-dione, was alkylated by the 4-chloromethylisoxazole (425). The octalindione (426) was treated sequentially with one equivalent of sodium borohydride, hydrogenated, hydrogenolyzed and refluxed with sodium methoxide and then with sodium hydroxide to afford the crystalline enone (427). 

Formation of an enamine radical cation 45 was proposed as the chain initiation step in the autooxidation of enamines and SchifFs bases of a,/ -unsaturated ketones to give unsaturated 1,4-diones37. Pyrrolidine enamine of 10-methyl-A1(9)-octal-2-one (44) reacts with oxygen at room temperature to produce, after acid hydrolysis, 10-methyl-A1 (9)-octalin-2,8-dione (47) in 20% yield. Addition of a catalytic amount of FeCl3, Cu(OAc)2 or CuCl2 causes a pronounced enhancement in the oxidation rate and increases the yield to 80-85% after 1 h. 

A gas chromatography column packed with Apiezon L suspended on Chromosorb P was employed for this analysis. In a typical analysis at 140° the retention times were A1,9-octalin, 46.2 minutes A910-octalin, 49.2 minutes. The n.m.r. spectrum (CC14 solution at 60 mHz.) of this mixture exhibits a multiplet at S 0.8-2.6 (aliphatic CH) with a weak, partially resolved multiplet at <5 5.25 (vinyl CH of A1,9-octalin). 

Introduction of functionalized angular methyl groups.2 The reaction of ethyl vinyl ether with 10-methyl-A1 <9 -2-octalol (1) catalyzed by mercuric acetate in a sealed Carius tube for 12 hr. at 200° gives 9-formylmethyl-10-methyl-A1-octalin (2, 85% yield) together with some dienes (3,15 % yield). Use of phosphoric acid leads only to the dienes (3). The one-step procedure involves formation of the vinyl ether followed by Claisen... 

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