Highly functionalized glyco-conjugated hexahydroazepindiones from saccharide imides via the Norrish type II reaction.
Starting from readily available protected 6-tosylates of D-glucose and D-mannose in both their pyranoside and furanoside forms as well as 6-tosylates of alpha-D-galactopyranose, the corresponding primary succinimido derivatives were obtained in good yield by nucleophilic displacement with potassium succinimide. These imido sugars were photochemically transformed into hexahydroazepindione derivatives such as by means of a Norrish type II reaction. As expected, the intramolecular alkylation proceeded via an 1,6 H-abstraction leading to a stabilized diradical. The regiochemistry of the photoreaction was controlled by configurational, conformational and electronic features and was sometimes influenced by the protecting groups. Using this route, a facile approach to a novel class of highly functionalized sugar derived heterocycles was developed.
Stark
Markus
M
Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany.
Thiem
Joachim
J
D000478:Alkylation; D001381:Azepines / Q000737:chemistry*; D005947:Glucose / Q000031:analogs & derivatives; D008358:Mannose / Q000031:analogs & derivatives; D010777:Photochemistry; D013388:Succinimides / Q000138:chemical synthesis; D014105:Tosyl Compounds / Q000737:chemistry
D001381:Azepines; D013388:Succinimides; D014105:Tosyl Compounds; D005947:Glucose; D008358:Mannose