Marine sponges of the genus dysidea and the marine cyanobacterium Lyngba majuscula are the source of a diverse subgroup of halogenated natural products in which the halogens are located at aliphatic positions.[1] For the majority of chlorinated natural products, the halogen atoms occupy positions that are suggestive of electrophilic chlorination as the biosynthetic origin of halogenation.[2] In contrast, the trichloromethyl group in a number of ...