ORGANIC MASS SPECTROMETRY, VOL. 26, 799-803 (1991) zyxwvut Mass Spectra of Some Per-0-benzoyl-alditols and -aldobiitols Norma B. D'Accorso and Inge M. E. Thiel Departamento de Quimica Organica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabell6n zyxwvutsrq 11, 3", 1428 Buenos Aires, Argentina Electron impact mass spectra of some per-0-benzoyl-alditols and -aldobiitols are reported and the major fragmen- tation pathways are discussed. INTRODUCTION The mass spectra of acetylated cyclic' and acyclic2 monosaccharide derivatives and those of benzoylated aldopyranoses and furanoses3 have been reported. The reported mass spectra of acyclic benzoylated derivatives have been limited to aldononitriles having three to six carbon chains and to the related 5-(polybenzoyloxy alkyl) tetra~oles.~ Thompson and Cory' reported only a few fragments of the mass spectra of some per-0-ben- zoylated alditols. The fragmentation pathways proposed for penta-0- benz~ylaldopyranoses~ and per-0-benzoylalditols are now employed for the interpretation of the mass spectra of more complex molecules, such as the per-0-benzoyl- aldobiitols. These compounds show the fragmentation of the glycosidic bond and each of the fragments formed gives a characteristic fragmentation pattern. RESULTS AND DISCUSSION deoxyalditols shown in Fig. 2 (10 and 11) and for the per-0-benzoylaldobiitols shown in Fig. zyx 3 (12-17). The mass spectra of these substances, like those of other polybenzoylated compounds, do not show the molecular ion owing to the easy loss of benzoic acid. Successive losses of benzoic acid and benzoic anhydride are character is ti^,^.^ the base peak being the ion of m/z 105 [PhCO]'. Also, intense peaks of m/z 331 [(PhCO),O] zyxwv +, m/z 227 [(PhCO),OH] +, m/z 122 [PhCO,H]+ and m/z 106 [C,H,CO]+ are common in the mass spectra of all the perbenzoylated compounds, and they are not of diagnostic value. A general fragmentation pathway for the sugar chain allows the correlation between chains of different z H2C-OCOPh H-C-OCOPh H-C-OCOPh PhCOO-C-H PhCOO-C-H CH3 10 - H C-OCOPh 21 FH , OCOPh CH3 11 - The electron impact ionization mass spectra (see Tables 1 and 2) were measured for the per-0-benzoylalditols shown in Fig. 1 (compounds 1-9), the per-0-benzoyl- - 10: penta-0-benzoyl-6-deoxy-pnannitol. - 11: 1,2(~,~~-di-g-benzoyl-propanodiol. Figure 2. Structures of compounds 10 and 11 H2C-OCOPh H-C-OCOPh PhCOO-C-H PhCOO-C-H H2C-OCOPh H2C-OCOPh H2C-OCOPh H-C-OCOPh H-C-OCOPh PhCOO-C-H I I PhCOO-C-H PhCOO-C-H PhCOO-C-H I I PhCOO-{-H H-C-OCOPh H-C-OCOPh H-C-OCOPh H-C-OCOPh H-C-OCOPh H2C-OCOPh H2C-OCOPh H2C-OCOPh H2C-OCOPh I 1 3 4 2 - - - - H2C-OCOPh H-C-OCOPh H-C-OCOPh H-C-OCOPh H2C-OCOPh I I I zyxwvu 5 H2F-OCOPh H-C-OCOPh I PhCOO-C-H H-C-OCOPh H2L-OCOPh 6 - H2$-OCOPh H2C-OCOPh H2F-OCOPh H2C-OCOPh I PhCOO-C-H H-C-OCOPh H-C-OCOPh I I H- OCOPh H-C-OCOPh PhCOO-C-H H2C-OCOPh H-C-OCOPh H2C-OCOPh H2C-OCOPh H2&-OCOPh c- Y zyxwvuts 1 zyxw 7 8 9 - - - - 1: hexa-2-benzoyl-pgalactitol; - zyxwvutsr 2: nexa-g-benzoyl-P-glucltol; 2: hexa-2-benzoyl-g-mannltol; - 4: penta-pbenzoyl-L-arabinitol; - 5: penta-2-benzoyl-g-rlbitol; 5: penta-g-benzoyl-g-xylitol; - 7: tetra-2-benzoyl-g-erythrytol; 8: tetra-g-benzoyl-g,&-threitol; 9: tri-pbenzoyl-glycerol. Figure 1. Structures of compounds 1-9 003M93X/91/090799-05 $05.00 zyxwvut 0 1991 by John Wiley & Sons, Ltd. Received 2 January 1991 Revised manuscript received 29 April 1991 Accepted 29 April 1991