Graduation Year

2024

Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts

Department

Chemistry

Reader 1

Daniel J. O'Leary

Reader 2

Jane M. Liu

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© 2023 Fernando C Cano

Abstract

Methanol titrations of partially deuterated diols dissolved in non-polar solvents such as CD2Cl2 and benzene-d6 provide 1H NMR measurements of OH/OD isotope shifts, diagnostic for intact or non-intact intramolecular hydrogen bonds under conditions of increasing protic solvent concentration. 1,6-diols (1-3) have been prepared from 2-adamantanone (4) and their structures characterized with 1H and 13C NMR, IR, HRMS, and x-ray crystallography (Figure 1). Isotope shifts in these systems, which are models of labile intramolecular hydrogen bonds, can be titrated to zero when in the presence of excess methanol equivalents. This is consistent with intramolecular hydrogen bond rupture under these conditions. These 1,6-diols therefore behave differently from conformationally rigid 1,3- and 1,4-diols, whose intramolecular OH/OH hydrogen bonds remain intact in the presence of excess methanol. We have also discovered evidence for intramolecularly hydrogen bonded enol 5, a functional group array more commonly found in -dicarbonyl compounds. This project will cover a bottom-up approach which starts at the synthesis of the 1,6-diols and ends with titratable OH/OD isotope shifts. The synthesis of the 1,6-diols was prioritized to save energy, time, and resources required for the subsequent NMR titration tests. A new synthesis for diol 3 is proposed with the purpose to save time and yield more mass. From these synthetic efforts it would best to see how greener the process can be made and how else we can alter our families of diols.

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