Abstract of the Disclosure: Compounds of the formula I ##STR1## where R.sup.1 is H or C.sub.1 -C.sub.4 -alkyl, R.sup.2 is C.sub.1 -C.sub.4 -alkyl and R.sup.3 is an ether, silyl ether or acetal protective group which can be converted into a hydroxyl group by hydrolysis, in particular one of the radicals ##STR2## and a process for preparing these compounds by reacting an alkenyne of the formula II ##STR3## in an inert solvent in the presence of lithium amide with a cyclohexenone of the formula III ##STR4## and the use of the compounds of the formula I for preparing astaxanthin, are described.
本发明公开了一种I式化合物:##STR1## 其中R1为H或C1-C4烷基,R2为C1-C4烷基,R3为醚、
硅醚或
缩醛保护基,可通过
水解转化为羟基,特别是其中的一个基团:##STR2## 以及通过在惰性溶剂中存在
锂酰胺的情况下,将II式烯炔化合物:##STR3## 与III式
环己酮反应制备这些化合物的过程。本发明还公开了利用I式化合物制备
虾青素的用途。