| abstract |
Disclosed herein is a process for the preparation of a quinone derivative represented by the following formula:n n wherein R¹ and R² are identical with or different from each other and mean individually a lower alkyl or lower alkoxy group, or may form an aromatic ring together, R³ denotes a lower alkyl group, n stands for 0 or an integer of 1-9, and a linkage --- is a single or double bond, such as a vitamin K derivative or coenzyme Q derivative, in high yields without forming any geometric isomer, wherein a Retro Diels-Alder reaction is employed, as well as a 1,4,4 a ,8 a -tetrahydro-4 a α-alkenyl-1α,4α-methanonaphthalene-5,8-dione derivative which is useful as an intermediate for the preparation of the quinone derivative. |