New Mass Spectra
Mass Spectra of Substituted Dihydrochalcones
The search for non-caloric, non-cariogenic sweetening agents is being actively pursued worldwide. The dihydrochalcones are ideal candidates for sweetener development owing to their intense sweetness (300-600 times that of sucrose), stability, safety and potential economic production.'** A number of novel dihydrochalcones have recently been prepared while investigating structure-activity relationships of dihydrochalcone sweeteners3 The synthesis of these structures utilized aldol condensations between appropriately functionalized, 2,4,
6-tris(benzyloxy)acetophenones
and 6-substituted-3benzyloxy-4-methoxybenzaldehydes. Intermediate chalcones were hydrogenated to give the product dihydrochalcones.
Mass spectra were obtained using a Finnigan 4000 gas chromatograph/mass spectrometer (Finnigan MAT, San Jose, CA, USA) using 70-eV electron impact (El) ionization. The samples were all solids and were introduced into the mass spectrometer using the direct insertion probe. Fast atom bombardment (FAB) and high-resolution mass measurements were obtained using a Kratos MS-50 mass spectrometer (Kratos Analytical Instruments, Manchester, UK). The FAB mass spectra were obtained using a glycerol matrix and a xenon atom beam at 7-8 keV with an ion current of -1 mA.
Electron impact mass spectra of eleven substituted dihydrochalcones are presented in Table 1. These compounds were confirmed by high-resolution mass measurements (EI, 1-3, 5-9, 11; chemical ionization (CI), 10; FAB, 4).3 The mass