280
2
General Synthetic Methods
parent ketohexoses such as, for example, fructose [3,23]. The 3,8-anhydro derivative 24, was
isolated during the synthesis of D-glycero-D-manno-oct-3-ulose (23) by self-aldol condensation of D-erythrose (22) ( > Fig. 6).
⊡ Figure 5
Examples of higher anomeric anhydrosugars
⊡ Figure 6
Selected examples of anhydroketoses
2.3 1,2-Anhydrosugars
1,2-Anhydrosugars are an important class of compounds in which the three-membered oxirane
ring is connected to the anomeric and the C-2 atoms of a sugar. The first compound of this
class, the so-called Brigl’s anhydride (26), was prepared by treatment of β-chloro-3,4,6-tri-Oacetyl-D-glucose (25) with ammonia ( > Scheme 11) [3].
⊡ Scheme 11
2
General Synthetic Methods
parent ketohexoses such as, for example, fructose [3,23]. The 3,8-anhydro derivative 24, was
isolated during the synthesis of D-glycero-D-manno-oct-3-ulose (23) by self-aldol condensation of D-erythrose (22) ( > Fig. 6).
⊡ Figure 5
Examples of higher anomeric anhydrosugars
⊡ Figure 6
Selected examples of anhydroketoses
2.3 1,2-Anhydrosugars
1,2-Anhydrosugars are an important class of compounds in which the three-membered oxirane
ring is connected to the anomeric and the C-2 atoms of a sugar. The first compound of this
class, the so-called Brigl’s anhydride (26), was prepared by treatment of β-chloro-3,4,6-tri-Oacetyl-D-glucose (25) with ammonia ( > Scheme 11) [3].
⊡ Scheme 11