Based on the reductive, stereospecific ring closure of (2R,4R,8'R)-a -'Tocopherylquinone' or corresponding analogues with a short, functionalized side chain (B, Scheme 1 ) to 1 resp. the chroman system of 1 (C), two different approaches for the introduction of the required tertiary methyl-substituted alcohol structure in the side chain of the aromatic precursors (A, Scheme 1 ) were developed. The first approach uses asymmetric alkylation in three different versions featuring a ) diastereoselective steering with chiral auxiliaries I-IV (Scheme 2) attached as esters to a-keto acids, b ) intermediate transfer of chirality in an ester enolate (from 18, Scheme 4 ) derived from an optically active a -hydroxyacid, c) enantioselective alkylation of phytenal (20) and subsequent ring closure with chirality transfer (Schemes 5-7). The second approach is based on the asymmetric epoxidation of ~-metallylalcohol (Sharpless epoxidation), the corresponding epoxyalcohol being converted in situ to the (S)-or (R)-chlorodiol (S)-and (R)-29, respectively, for isolation (Schemes 8 and 9 ) . Nucleophilic epoxide opening with a (3R,7R)-3,7,11-trimethyldodecyl (Cy;*) and an ArCH, unit in appropriate sequence is used to assemble the C-framework of the target molecule via corresponding epoxide intermediates from either chlorodiol. Combined with the use of the methoxymethyl-ether function for protection of the hydroquinone system, the epoxide approach provides a short route to 1 (Scheme 10). Einleitung