Diastereo and Enantioselective Synthesis of 1,2-Diols Promoted by Electrophilic Selenium Reagents
摘要:
Here we report the first example in which the phenylseleno group is directly substituted by a hydroxy function. The reaction is promoted by the PhSeOSO3H generated "in situ" by oxidation of (PhSe)(2) with (NH4)(2)S2O8 at reflux in a 3:1 mixture of MeCN-H2O. Interestingly the reaction can be performed in "one pot" using a catalytic amount of diselenide affording the corresponding diols (5 and 6) with good yield and good level of diastereo- and enantioselectivity.
Synthesis of terpenyl selenides derived from limonene, menthol, caranol, and myrtanol is described. Three methodologies for the synthesis of terpenyl selenonium salts are compared. The results of selenium-mediated epoxidation through the use of isoselenocineole derived from limonene and methyl terpenyl, phenyl terpenyl, diterpenyl selenides, and selenonium salts are presented. The influence of solvent