Synthesis of Vanillin from Clove Essential Oil: A 3-Day Laboratory Course on Organic Chemistry (Not Only) for Pharmacy Students Including Modern Aspects of Transition Metal Catalysis

Abstract

A laboratory course on organic chemistry is presented in the context of isolating and converting natural products for those interested in developing their laboratory curriculum and activities. The course features a robust 5-step laboratory synthesis of vanillin from cloves. It was designed at the Department of Chemistry Education at RWTH Aachen University and successfully implemented in the Bachelor’s program Pharmaceutical Management and Production at DIPLOMA University of Applied Sciences, where it was evaluated with 12 cohorts and a total of 112 second-year undergraduate students. The educational approach enables students to conduct the entire experimental process, from cloves to vanillin, overcoming limitations of an older laboratory synthesis published in this journal. Steps of the original procedure that proved too dangerous or unsuccessful were substituted, employing modern aspects of transition metal catalysis. The synthesis involves a wide range of typical laboratory operations that serve as learning objectives, including Soxhlet extraction, the use of rotary evaporators, vacuum distillation, vacuum filtration, crystallization, and purity testing using refractive index, melting point, and gas and thin-layer chromatography. The course offers opportunities to address basic principles of organic synthesis, such as retrosynthetic considerations, protective groups, or acid/base/transition metal catalysis, in the context of daily life natural products, which should increase student motivation and interest in these topics.