Synthesis of (R)-4,5-Dihydro-3H-Dinaphtho-[2,1-c:1',2'-e]Selenepin Oxide and Preliminary Studies on Its Use in the Oxidation of Sulfides

Abstract

The first synthesis (R)-4,5-dihydro-3H-dinaphtho-[2,1-c:1',2'-e]-selenepin oxide 1 has been achieved from (R)-(+)-1,1'-bi-2-naphthol, which in turn was obtained by resolution of rac-1,1'-bi-2-naphthol. Palladium catalyzed alkoxy-carbonylation of ditriflate 4 gave dimethyl ester 5 which was then reduced and the resultant diol converted to key intermediate chloride 8. Cyclization with sodium selenolate gave novel enantiomerically pure selenide 9, which upon oxidation yielded the desired selenoxide (R)-1. Preliminary studies on the oxidation of sulfides to sulfoxides using 1 and 2,2,2-trifluoroethane sulfonic acid are also described.