Intramolecular delivery of a nitrogen

Scheme 10-99 Intramolecular delivery of a nitrogen nucleophile provides the correct stereochemistry at the anomeric position for a synthesis of hydantocidin.

Scheme 10-100 Intramolecular delivery of a nitrogen nucleophile allows stereospecific incorporation of the amino functionality at the sterically hindered C(6) position.

In a new approach to 2 -amino-2 -deoxyuridine (70) and related compounds, involving intramolecular delivery of a nitrogen nucleophile, the anhydronucleo-side 69 was treated as outlined in Scheme 6. The cytidine analogue was also prepared. In a similar way (Scheme 7), 2 -alkoxyamino derivatives could be made from -alkoxyurethanes, and the same type of cyclization was possible with A -alkylurethanes, but required more vigorous conditions. ... 

---