Catalytic diastereo- and positionselective oxidative mono-cyclization of 1,5,9-trienes and polyenes

Ruthenium tetroxide (1 mol%) has been used as a catalyst for the oxidative mono-cyclization of 1,5,9-trienes and polyenes. The poly-unsaturated substrates underwent mono-cyclization with a high degree of diastereo- and positionselectivity to produce mono-tetrahydrofuran diols with a varying degree of unsaturation. Up to four new stereogenic centers were created in this single step transformation. The remarkable positionselectivity appears to be a result of relative electronic properties of the double bonds within the polyolefinic substrates in conjunction with conformational constraints.