Stereocontrolled Synthesis of Phosphoproline Analogues Containing a trans -Fused Octahydroindole Bicyclic System.

Herein we report for the first time the diastereoselective synthesis of (2 R ,3a R ,7a S )- and (2 S ,3a S ,7a R )-octahydroindole-2-phosphonic acid (Oic P trans -fused stereoisomers) from diethyl ( R )- and ( S )-phosphopyroglutamate derivative. The key steps of this procedure are the ruthenium tetroxide oxidation of enantiomerically pure diethyl ( R )- and ( S )-phosphoprolinate obtained through Katritzky's benzotriazole-oxazolidine methodology, a highly diastereoselective successive double 4,5-diallylation of diethyl ( R )- and ( S )-phosphopyroglutamate with allyl bromide and allyltrimethylsilane with a trans -addition mode, and a ring-closing metathesis with Grubbs' first-generation ruthenium catalyst.