The concept of "green chemistry" or "sustainable chemistry" is aimed at obtaining the non-toxic chemical products for humans and environment, but also the use of renewable organic raw materials. Thus, interest in chemical product and process design that reduces or avoids the use/generation of harmful pollutants has grown considerably recently. Analyzing the development trends of the chemical industry in the 21st century, we notice that ecological methods are used to obtain biologically active preparations. Recently, interest in the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones (Biginelli compounds) and their derivatives has increased enormously due to their various therapeutic and pharmacological properties, such as antiviral, antibacterial, and antitumor remedies. Some of them have been successfully used as calcium channel blockers, neuropeptide antagonists, etc. Monastrol –a natural chiral bioactive compound- is an important target molecule for organic chemists due to its remarkable biological properties, for example antitumor activity and inhibition of the motility of the mitotic motor protein kinesin Eg5, thus serving as a useful tool for studying the mechanisms of mitosis. The most useful and smart method actually applied for monastrol synthesis is the Biginelli multicomponent reaction, discovered in 1891 by Pietro Biginelli. This paper presents the results of the efficient preparation with a high yield of monastrol by using an ecologically convenient approach involving the combination of the "green" solvent - ethanol and the "green" catalyst - citric acid.