Glycal Derivatives
3.6
715
⊡ Scheme 20
⊡ Scheme 21
⊡ Scheme 22
⊡ Scheme 23
⊡ Scheme 24
Glycals can also be obtained in a one-pot reaction from 2-deoxyhexopyranoses having a free
hydroxyl at C-1. An example of such a transformation is high-yield (89%) synthesis of triO-benzyl-D-glucal 73 from 2-deoxy-3,4,6-tri-O-benzyl-D-glucopyranose 72 via 1-O-mesylate
( > Scheme 24) [165].
An interesting demonstration of base-catalyzed cis elimination leading to 3,4,6-tri-O-acetylglucal (4) used O,O-dimethyl-S-(3,4,6-tri-O-acetyl-2(R)-2-deoxy-2-deuterio-α-D-arabinohexopyranosyl)phosphorodithioate 72 ( > Scheme 25) [166].
3.6
715
⊡ Scheme 20
⊡ Scheme 21
⊡ Scheme 22
⊡ Scheme 23
⊡ Scheme 24
Glycals can also be obtained in a one-pot reaction from 2-deoxyhexopyranoses having a free
hydroxyl at C-1. An example of such a transformation is high-yield (89%) synthesis of triO-benzyl-D-glucal 73 from 2-deoxy-3,4,6-tri-O-benzyl-D-glucopyranose 72 via 1-O-mesylate
( > Scheme 24) [165].
An interesting demonstration of base-catalyzed cis elimination leading to 3,4,6-tri-O-acetylglucal (4) used O,O-dimethyl-S-(3,4,6-tri-O-acetyl-2(R)-2-deoxy-2-deuterio-α-D-arabinohexopyranosyl)phosphorodithioate 72 ( > Scheme 25) [166].