A general synthetic methodology has been developed for the synthesis of a conformationally locked, bridged diselena-bicyclo[3.2.1]octane skeleton by regio- and stereospecific tandem nucleophilic ring opening of cis-1,4-aziridino-epoxides with tetraethylammonium tetraselenotungstate [Et4N](2)WSe4, 1, in a one-pot synthesis. Some correlations have been made on the physicochemical characteristics of the diselenides with a change in the dihedral angles.
Synthesis of enantiopure bis-aziridines, bis-epoxides, and aziridino-epoxides from d-mannitol
摘要:
A practical synthesis of enantiopure bis-aziridines 11 and 15, bis-epoxides 12 and 17, and aziridino-epoxides 27 and 30 is reported using inexpensive D-mannitol as the starting material. The key transformation involves the reductive cleavage of bis-benzylidene acetal 3 to form dimesylate 4, which was further converted to monoazides and diazides followed by reduction, mesylation, and cyclization to furnish the required compounds in good yields. (c) 2006 Elsevier Ltd. All rights reserved.