The following reaction is attempted without any solvent by grinding the solid reactants with solid NaOH. Analysis of the product mixture revealed the molecular formula to be C18H18O4. The product mixture may contain

The given formula of the product corresponds to aldol products. As both stereo genic centers are generated form sp2 carbons all four stereoisomeric products would be formed.or in simple words, carbanion ion can undergoes tautomerism, resulting in C=C, which is planar, hence the product can be formed above the plane or below the plane.