| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the subject compound useful for carotenoids at a low cost by using a halogenated methyl lithium as a reagent. SOLUTION: (A) A protected 4-hydroxy-2,6,6-trimethyl-2-cyclohexen-1-one of formula I (R' is a hydroxy-protecting group) as a starting substance is reacted with (B) a halogenated methyl lithium (e.g. chloromethyl lithium) to obtain a protected compound of formula II (R is the protecting group R'), from which the protecting group is, removed, if desired. The component A I s preferably treated with a dihalogenated methane (e.g. bromochloromethane) and a lower alkyl lithium (e.g. n-butyl lithium) so as to simultaneously produce the component B in the reaction.</p> |
