Carbocyclic Ring Closure of an Aminodeoxy HEX-5-Enopyranoside

Ferrier's intramolecular carbocyclic ring closure reaction of methyl 3,4-di- O -acetyl-2-benzoyl-amino-2,6-dideoxy-α-O- xylo -hex-5-enopyranoside ( 2 ) led to 2L-2,4,513-2,3-di- O -acetyl-4-benzoylamino-5-hydroxy-cyclohexanone ( 4 ). Upon acetylation compound 4 underwent B-elimination to give the conjugated enone 5 . The convenient preparation of these highly functionalized aminocyclohexanones offers an efficient route to monoamino- or 1,4-diaminocyclitol-type aminoglycoside antibiotic aglycones, starting from 2-amino-2-deoxy-O-glucose.