The use of d-mannitol-derived C2-symmetric trienes in tandem metathesis reactions towards valuable lactones

Chiral lactones were synthesized from d-mannitol. C2-symmetric triene precursors were constructed with a central relay-olefin allowing the key domino ring-closing metathesis to be achieved. It led to the symmetrical cleavage of the substrate and to the formation of 2 mol of the desired 5- or 6-membered lactone. Attempts to form 7-membered lactones thus far only led to 14-membered macrodiolides instead.