A series of simplified thiomarinol derivatives was prepared by way of catalytic enantioselective inverse electron demand hetero [4+ 2] cycloaddition/allylboration tandem reaction. As a preliminary evaluation, these analogs were tested for antimicrobial activity using a standard disk diffusion assay. Whereas amide analogs were less active, the simple ester analogs 3 and 4 were demonstrated to be more active than thiomarinol H.