Chemo-enzymatic enantioconvergent approach toward ethyl shikimate from ethyl 5-hydroxy-3,4-isopropylidenedioxycyclohex-1-enecarboxylate

An enantioconvergent route for natural form of ethyl shikimate was achieved from Diels-Alder adduct of furan and acryloyl chloride. The key step was a highly enantioselective (E >500) and efficient acetylation of ethyl (3R*,4S*,5S*)-5-hydroxy-3,4-isopropylidenedioxycyclohex-1- enecarboxylate, which had a diastereomeric relationship with ethyl shikimate, mediated by Burkholderia cepacia lipase (Amano PS-IM). Both of the resolved enantiomers were converted to natural form of ethyl shikimate by inversion at C-5 for the former and at C-3 and C-4 for the latter, respectively.