A process for preparing compounds of the formula I
1
is described and entails converting a compound of the formula II
2
by Wittig or Wittig-Horner reaction into a compound of the formula IV,
3
where appropriate converting the compound of the formula IV by hydrolysis of the acetal function and Wittig or Wittig-Horner reaction into a compound of the formula VI
4
and converting the compound of the formula IV or VI in two stages into the compound of the formula I. The radicals R
1
, R
2
and R
6
and k have the meaning indicated in the description. Novel intermediates are also described.
                            描述了一种制备化合物I1的过程,包括通过Wittig或Wittig-Horner反应将化合物II2转化为化合物IV,3,必要时通过
水解
缩醛基团和Wittig或Wittig-Horner反应将化合物IV转化为化合物VI4,并将化合物IV或VI分两阶段转化为化合物I的过程。基团R1、R2和R6以及k在描述中有所指示。还描述了新的中间体。