4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid, 6-[[5-(acetylamino)-5-carboxy-1-oxopentyl]amino]-3,3-dimethyl-7-oxo-, [2S-[2α,5α,6β(R*)]]- (9CI) [ 94040-19-4 ]