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This preliminary work discusses the vibrational dynamics and intramolecular force field of DL-$\beta$-butyrolactone, a four-membered ring compound sometimes used as a precursor in drug syntheses. We have initiated a study and determination of possible simple valence force fields (VFF) for DL-$\beta$-butyrolactone. One approach is via MINDO calculations. Another approach is with vibrational spectroscopy (i.r. and Raman) and classical normal coordinate calculations. Except for C-H stretching frequencies and C-H valence stretching constants, the MINDO calculated frequencies are surprisingly close to observed vibrational frequencies. This is unusual for MINDO calculations on a strained ring. Results of the MINDO and normal coordinate $work1$ will be presented and contrasted with a previous study on $\gamma$-butyrolactone, which is a five-membered ring.