Isopropylidene 5-(3-oxo-alkyl)malonates (3) were synthesized by condensation of Mannich base of isopropylidene malonate with methyl ketones in the presence of faint acid, such as acetic acid.

• 5-烃基丙二酸亚异丙酯的Mannich碱和甲基酮在弱酸如醋酸的存在下；合成得到缩合产物5-(3-氧代烃基)丙二酸亚异丙酯(3).