Synthesis of a key intermediate for Thienamycin and Imipenem through stereoselective two-direction elongation of asymmetrized bis(hydroxymethyl)acetaldehyde (BHYMA∗)
The enantioselective formal synthesis of Thienamycin and Imipenem has been realised through two-direction elongation of the chiralbuildingblock bis(hydroxymethyl)acetaldehyde 5. The generation of the two additional stereocentres has been carried out with excellent diastereoselectivity thanks to two sequential “protecting group controlled” nucleophilic additions. Another key step was represented by