A mass-spectrometric study of 3′,4′-dihydroxy-and 3′,4′-diacyloxydihydropyranocoumarins

Conclusions

The mass spectra of 13 3′,4′-dihydroxy, 3′-hydroxy-4′-methoxy-, 3′-acyloxy-4′-methoxy-, and 3′,4′-diacyloxydihydropyranocoumarins have been studied. Schemes of the decomposition of these compounds leading to the formation of the main fragments in their mass spectra have been proposed. It has been shown that the mass spectra of (V–XIII) indicate whether the acyloxy groups are attached to position 3′ or 4′ of the dihydropyran ring. characteristic fragments with m/e 261, 245, 244, 243, 230, 229, 228, and 227 have been found, the positions and relative intensities of which form distinguishing features of the mass spectra of the diacyl derivatives of khellactone.