NEW MATERIAL:An optically active compound expressed by formula I [R1 to R3 are H or 1-4C alkyl; R4 and R6 are OH or protected OH, and further R4 is oxo (in said case, benzene ring has benzoquinone structure); R5 and R8 are OH or acyloxy, and further R5 is H; R7 is 1-4C alkyl, 1-4C alkenyl, 1-4C alkinyl or phenyl; steric configuration of chiral central carbon atom expressed by formula II and having * mark is independently either S- or R-configuration].
EXAMPLE: (1R/S, 3R, 5S)-6-benzyloxy-1,3,5-trihydroxy-1-(2,5-dimethoxy-3,4,6- trimethylphenyl)-3-methylhexane.
USE: Used as an intermediate freely control the stereoselectivity to produce tocopherol having natural or non-natural steric configuration from a readily available optically active compound.
PREPARATION: A new optically active compound expressed by formula III is reduced to obtain a new optically active compound expressed by formula IV, and the resultant compound is made to react with a compound expressed by formula V (Ra is a protecting group) to afford the optically active compound expressed by formula VI in the formula I.
OGASAWARA KUNIRO