A process for the preparation of a monoalkylidene substituted 1,4-dions derivatives of formula (Ia) or (Ib) or a mixture of (Ia) and (Ib): wherein: R
1
, R
2
and R
3
, equal to or different from each other, are hydrogen atoms or C
1
-C
20
hydrocarbon groups: T
1
and T
2
, equal to or different from each other, are OR
4
, R
4
, NR
4
2
, SR
4
or PR
4
2
; or T
1
and T
2
can be fused in an oxygen atom or a NR
4
group; said process comprises the step of reacting a compound of formula (II) with a compound of formula (IIIa) or (IIIb) in the presence of at least one equivalent with respect to the compound of formula (IIIa) or (IIIb) of a carbonate of metal M or of a compound of formula MT
j
such as K
2
CO
3
or KHCO
3
.
一种制备式(Ia)或(Ib)或(Ia)和(Ib)混合物的单亚烷基取代的 1,4-二
酮衍
生物的工艺: 式中R
1
, R
2
和 R
3
相互相等或不同,为
氢原子或 C
1
-C
20
烃基:T
1
和 T
2
相等或不同,为 OR
4
, R
4
、NR
4
2
, SR
4
或 PR
4
2
或 T
1
和 T
2
可以融合在一个
氧原子或一个 NR
4
基团;所述工艺包括以下步骤:在至少一种等同于式(IIIa)或(IIIb)化合物的
金属 M 的
碳酸盐或式
MT 的化合物存在下,使式(II)化合物与式(IIIa)或(IIIb)化合物反应
j
如 K
2
CO
3
或 KHCO
3
.