First totalsynthesis of the polyhydroxy 5,6-dihydro-2H-pyrone containing natural products monticolide A and B is reported from tartaric acid. Key reaction is the iridium catalysed redox reaction of the Achmatowicz reaction product to the 5,6-dihydro-2H-pyrone moiety and the use of tartaric acid as a four hydroxy four carbon synthon.