Synthesis of chloroquinocin, a pyranonaphthoquinone antibiotic against Gram-positive bacteria

Chloroquinocin 1 is an antimicrobial agent against Gram-positive bacteria, including MRSA (methicillin-resistant Staphylococcus aureus). A successful synthesis of 1 was attained through a unique chlorination of the corresponding naphthoquinone derivative 12 as a key step.