1-Azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid,3-[[1-[2-[(3,4-dihydroxyphenyl)amino]-2-oxoethyl]-3-pyrrolidinyl]thio]-6-(1-hydroxyethyl)-4-methyl-7-oxo-, 2-propenyl ester