Hex-1-en-3-uloses were prepared from fulled-protected glycal either by direct oxidation with in situ generated Koser’s reagent or by a three-step procedure involving global deacetylation, selective allylic oxidation with pyridinium dichromate, and acetylation(benzoxylation).
??-enamino ketones were successfully synthesized in good to excellent yields by reaction of hex-1-en-3-uloses with amines. After hydrogenation on palladium catalyst, ??-enamino ketones effectively underwent hydrodeamination.
We succed to reduce the????-enamino ketone by Zn powder in AcOH to affore the????-amino ketone and follow by hydroxyl group trans to –OTf and sequent cyclization to give the fagomine.
