| abstract |
1477122 2,6,10-Trimethylundecyl and 2,6,10- trimethylundecenyl ethers F HOFFMANN-LA ROCHE & CO AG 27 Jan 1976 [27 Jan 1975] 03080/76 Headings C2C and C2J The invention comprises compounds of general Formula I where R 1 is an ether group that is convertible by hydrolysis or hydrogenolysis into the hydroxy group, and the broken line denotes an optional bond. These compounds may be prepared by reacting a compound of Formula III in the presence of an organic solvent and of a di- (alkali metal)-tetrahalocuprate with a compound of Formula IV where one of A and B is -MgX and the other is a group Y where X is a halogen atom and Y a leaving group; either m is 1 and n is zero, or m is zero and n is 1. R 1 is for example 4-methyl-5,6- dihydro - 2H - pyranyloxy, tetrahydropyranyloxy, benzyloxy, benzhydryloxy, trityloxy, an α-(lower alkoxy)-lower alkoxy group (e.g. methoxy-methoxy), allyloxy, a trialkyl-silyloxy group (e.g. trimethylsilyloxy) or t-butoxy. The leaving group Y is for example an alkyl or aryl sulphonyloxy group. The invention is exemplified by the preparation of 2(R), 6(R)-(+)-1-tbutoxy, 2,6,10-trimethyl-undecane; this compound is a precursor of α-toropherol, the synthesis of the benzyl ether of which is described. The syntheses of starting materials of Formulµ III and IV and their precursors are also described. |