A short approach to the bicyclo[4.3.0]nonane fragment of stawamycin

The bicyclo[4.3.0]nonane (C11–C21) fragment of stawamycin has been prepared by a sequence involving 11 steps (10% overall yield) from methyl (R)-(−)-3-hydroxy-2-methylpropionate. Key steps are a Pd-catalysed Stille coupling reaction between a vinyl iodide and a vinyl stannane followed by an intramolecular Diels–Alder cycloaddition reaction to give the desired adduct as the major isomer in 21% overall yield.