PURPOSE: To prepare the titled compound useful as an intermediate for the preparation of vitamin K1, K2, coenzyme Q, etc., in high selectivity, suppressing the side reactions effectively, by reacting a phosphoric acid ester with a hydroquinone derivative in the presence of a Lewis acid keeping the reaction temperature at a low level.
CONSTITUTION: A hydroquinone derivative of formula IV (e.g. 1,4-dimethoxy-2- geranyl-3-methyl-naphthalene) is prepared by reacting a phosphoric acid ester of formulaI[n is 0W9; Ar is (substituted) phenyl; the dotted line is single or double bond], e.g. geranyl disphenyl phosphate, with a hydroquinone derivative of formula II (R1 is protecting group; R2 is methyl, methoxy, or two R2s may together form the group of formula III)(e.g. 1,4-dimethoxy-2-methylnaphthalene) in the presence of a Lewis acid at about -80W0°C, pref. about -80W-30°C.
HAMANAKA TATSUROU
ARAKI NAOKI
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