Astaxanthin was synthesized from α-ionone via the route of 2C₁₅＋C₁₀→C₄₀. In which the key intermediate of C₁₅ building block, 6-hydroxy-3-(3-hydroxy-3-methyl-1,4-pentadien-1-yl)-2,4,4-trimethyl- 2-cyclohexen-1-one was obtained by selectively epoxidizing the double bond of trimethylsilyl enol ether as a key step.

Key words: α-ionone, astaxanthin, carotenoid, 2,7-dimethyl-2,4,6-octantrien-1,8-dial, 6-hydroxy-3-(3-hydroxy-3-methyl-1,4-pentadien-1-yl)- 2,4,4-trimethyl-2-cyclohexen-1-one