Andrew Dressner ‘22
Name: Andrew Dressner
Major: Natural Science
Biography: Andrew is a current senior majoring in Natural Science with a minor in philosophy. He is on the pre-health track and will be attending medical school in the fall after graduation. In addition to working in the lab with Dr. Di Grandi, Andrew is the photo editor of The Observer, the student newspaper, and the president of LC Emergency Medical Services Club. In his free time, Andrew enjoys photography and rock climbing.
Project Title: An Intramolecular Friedel-Crafts Alkylation of N-Benzyl Aziridines: A Novel Synthetic Method with an Application Toward the Total Synthesis of (±)–Pancratistatin
Faculty Mentor: Martin Di Grandi, Department of Natural Sciences
Abstract: Pancratistatin, a member of the Amaryllidaceae family of natural products, was originally isolated from a Hawaiian spider lily and subsequently found to have unique anti-cancer properties. While several published syntheses of this compound have been reported, this research explores the potential use of N-benzyl aziridines as precursors to 1,2,3,4-tetrahydroisoquinolines, part of the core ring system of this natural product.
Earlier we demonstrated that subjecting N-benzyl aziridines to either TsCl/AgOTf or triflic acid was sufficient to effect a rearrangement that afforded 1,2,3,4-tetrahydroisoquinolines. We have expanded this chemistry to include more highly functionalized starting materials, which as expected, permitted the use of weaker acids for activating the rearrangement. Additionally, this modification has the potential to render the sequence enantioselective when effected with chiral sulfonic acids.
Overall, application of this ring expansion methodology to more highly functionalized N-benzyl aziridines has defined milder reaction conditions, which can potentially render the reaction enantioselective, allowing more control of the product produced.