In the First Semester Topics of organic chemistry, we introduced CRIXIVAN® (Indinavir Sulfate), the HIV protease inhibitor developed at Merck. By examining its synthesis and development, we explored foundational organic chemistry topics such as bonding, stereochemistry, and reaction mechanisms, all of which are crucial for understanding the structure and reactivity of organic molecules. These concepts provided the tools to begin appreciating how chemists design and build molecules with specific purposes, like life-saving drugs.
As we move into the second semester of organic chemistry, our focus shifts toward transformations and concepts that are particularly important in biological systems and advanced synthetic design. We will explore reactions of alcohols and epoxides, learning how these versatile functional groups can serve as intermediates in multi-step syntheses. Arenes and the principles of aromaticity will reveal the unique stability of aromatic compounds and provide insight into their reactions, including electrophilic aromatic substitution, a key transformation in both biological and industrial contexts. The chemistry of aldehydes and ketones will deepen our understanding of carbonyl reactivity, from nucleophilic additions to enolate chemistry, which is central to carbon-carbon bond formation in both metabolic pathways and laboratory synthesis.
Carboxylic acid derivatives will highlight the diversity of functional groups derived from carboxylic acids, showcasing their interconversion and reactivity in esterifications, amidations, and beyond. We will also examine key reactions such as aldol condensations, Claisen condensations, and Michael additions—essential tools for building complex molecular frameworks. Finally, pericyclic reactions will bring us full circle, emphasizing the elegant concerted electron flow involved in cycloadditions, electrocyclic reactions, and sigmatropic rearrangements. These transformations not only play a pivotal role in laboratory synthesis but are also fundamental to the processes that sustain life.
Throughout the second semester, we will continue to revisit CRIXIVAN as a unifying example, examining how the advanced topics we study—such as enolate alkylations, stereoselective aldol reactions, and aromatic transformations—relate to its synthesis and the development of similar therapeutic agents. By bridging these chemical transformations to real-world applications in drug discovery and biological systems, we aim to connect the theoretical to the practical and the molecular to the biological.
Second Semester Topics is where the tools and concepts come together to form a cohesive picture of how chemists manipulate molecules to solve problems, whether in the lab or in living systems.