To provide a process for increasing the proportion of an optical isomer of not only a compound having a closed ring but also a compound not having a closed ring when an optical isomer mixture of a compound having both a formyl group and a double bond capable of causing a carbonyl-ene ring closing reaction in the same molecule is subjected to a ring closing reaction. A process for increasing the proportion of an optical isomer characterized by subjecting an optical isomer mixture of a compound having both a formyl group and a double bond capable of causing a carbonyl-ene ring closing reaction in the same molecule to a ring closing reaction in the presence of a predetermined aluminum complex represented by the general formula: [Al2(L1)n(L2)3-n]m.
提供一种增加光学异构体比例的过程,不仅适用于具有闭环的化合物,也适用于不具有闭环的化合物,当具有
甲醛基和能够在同一分子中引起羰基-烯烃环闭合反应的双键的化合物的光学异构体混合物经过环闭合反应时。一种增加光学异构体比例的过程,其特征在于将具有
甲醛基和能够在同一分子中引起羰基-烯烃环闭合反应的双键的化合物的光学异构体混合物在预定的铝配合物存在下进行环闭合反应,该铝配合物由通式表示:[A
L2(L1)n(
L2)3-n]m。