Supporting Information for: "Synthesis and characterization of γ-alkanoyl-ε-caprolactones" (SI-3)
The authors contributed equally to the work.
Description
This dataset contains the raw, unprocessed NMR data for the title compounds of the paper "Synthesis and characterization of γ-alkanoyl-ε-caprolactones" published in iScience (DOI: [XXX ADD DOI XXX]. NMR spectra were acquired on a JEOL-ECZS 400 MHz spectrometer in CDCl3 (Cambridge Isotope Labs, 99.8% D) and are saved in the .jdf format. Chemical structures in this document will be represented in the SMILES format. The paper details the synthesis of eight lactones, with variation of the exocyclic ester. Within this set, we consider CC(OC(CC1)CCOC1=O)=O (7-oxooxepan-4-yl acetate or γ-acetyl-ε-caprolactone) to be the parent compound. The R group pendant from the exocylic carbonyl in this compound is a methyl. We also prepared R = Et, n-Pr, i-Pr, i-Bu, t-Bu, CMe2Br, and Ph. Of these, R = CMe2Br has been extensively prepared and characterized, R = Me has conflicting NMR data in the primary literature (see below), and the other compounds are unreported. This data set includes 1H, 13C, COSY, HMBC, HMQC spectra for all new or incompletely characterized lactones (R = Me, Et, n-Pr, i-Pr, i-Bu, t-Bu, Ph.) and NOESY for R = Me and R = t-Bu. Within the paper, these compounds have are numbered as 5a (R = Me), 5b (R = Et), (5c) n-Pr, 5d (R=i-Pr), 5e (R = i-Bu), 5f (R = t-Bu), and 5h (R = Ph). The data is located in folders labeled by compound number and pendant R group (e.g. "5a_R=Me"). For R = Me, the NMR data in Canney et. al. (Gao, R.; Canney, D. J. Tet. Lett. 2009, 50 (43), 5914-5916. DOI: 10.1016/j.tetlet.2009.08.016) does not match does not match what we find. The report R = Me and several closely related compounds, all prepared by a different route. Their spectra all lack the characteristic methine resonance at ~5.1 ppm we observe for all γ-alkanoyl-ε-caprolactones. Our data for this compound match that of a more recent report by Stefan et. Al. (Kularatne, R. N.; Somayeh Taslimy, S.; Bhadran, A.; Cue, M. O.; Bulumulla, C.; Calubaquib, E. L.; Gunawardhana, R.; Biewer, M. C.; Stefan, M. C. Polym. Chem. 2023, 12, 3962-3970. DOI: 10.1039/d3py00388d). We believe Canney et. al. have prepared the isomeric γ-butyrolactones.