Pseudo-maltose

Because 6-deoxyhex-5-enopyranose derivatives can be readily converted into 2-deoxyinososes,91 5-bromides (for example, 164) give useful access to such carbocyclic compounds.92 In this way, octa-0-acetyl-/ -maltose was converted by treatment with zinc-acetic acid into the 5-ene by way of the corresponding 5-bromide 30 and thence into the pseudo-disaccharide compound (169) which is related to components of members of the aminoglycoside antibiotic series.36... 

Stahl and Parliment126, too, examined higher temperature reactions. They studied the glucose-proline system (0.2 M in each) in a continuous-flow reactor either at different times (0.25-5.0 min) at 200 °C or for 1.0 min at different temperatures (160-220 °C). The main volatile components identified at 200 °C after 0.25 min were only three 2-acetyltetrahydropyridine, 5-acetyl-2,3-dihydro-l//-pyrrolizine, and maltoxazine (see Scheme 5.3, p. 66). After 2 min the pyrrolizine dominated. The kinetics for each of the three compounds was pseudo-zero order. The activation energy of the pyrrolizine was 188 kJ (45 kcal) mol-1, much higher, as expected, than those of the other two compounds [25-63 kJ (6-15 kcal) mol-1]. The low value for maltoxazine fits with its presence in malted barley and its formation in aqueous glu-cose-Pro and maltose-Pro systems at boiling point.127... 

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