Synonyms: Cyclobutyldithymidine dimers;AC1L4Q1W;Cyclobutyl dithymidine dimers;Cyclobuta-dithymidine photoproducts;33407-74-8;Cyclobuta(1,2-d:4,3-d')dipyrimidine-2,4,5,7(3H,6H)-tetrone, 1,8-bis(2-deoxy-beta-D-erythro-pentofuranosyl)hexahydro-4a,4b-dimethyl-, (4aalpha,4balpha,8aalpha,8balpha)-