Ac acetyl Ar aryl Bn or Bzl benzyl Bu or n-Bu normal (primary) butyl s-Bu sec-butyl t-Bu tert-butyl Bz benzoyl (not benzyl) Et ethyl Me methyl Ph phenyl Pr propyl i-Pr isopropyl aq aqueous d chemical shift in parts per million downfield from tetramethylsilane DMF dimethylformamide DMSO dimethyl sulfoxide E1 unimolecular elimination E2 bimolecular elimination HOMO highest occupied molecular orbital HPLC high-performance liquid chromatography HRMS high-resolution mass spectrometry IR infrared J coupling constant (in NMR spectrometry) K kelvin(s) (absolute temperature) LAH lithium aluminum hydride LDA lithium diisopropylamide; LUMO lowest unoccupied molecular orbital mol mol MS mass spectrometry MW or mol wt molecular weight NBS N-bromosuccinimide NMR nuclear magnetic resonance Nu nucleophile rt room temperature redox reduction-oxidation R[f] retention factor (in chromatography) s singlet (spectral) S[N]1 unimolecular nucleophilic substitution S[N]2 bimolecular nucleophilic substitution t triplet (spectral) THF tetrahydrofuran TLC thin-layer chromatography TMS trimethylsilyl; tetramethylsilane t[R] retention time (in chromatography) UV ultraviolet vis visible