Without Cleavage of Te —C Bond

Figure 15 Stereochemistry of the condensation step in erythromycin biosynthesis. Experiments with bimodular DEBS 1-TE in vitro have demonstrated that condensation of (2S)-methylmalonyl-CoA in module 2 proceeds with decarboxylative inversion without cleavage of the C—H bond adjacent to the methyl group. The results are also consistent with the same stereochemistry of condensation, inversion, in module 1, followed by epi-merization of the resulting D-methyl center to the required L-methyl configuration in the P-keto intermediate.

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