A method of chemical synthesis of a compound of Formula: comprising a step of periodate mediated oxidative coupling, in which a compound of Formula: is reacted with a compound of Formula: and a periodate oxidising agent; to form said compound of Formula; wherein: - R 1A1 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 1A2 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 1B1 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 1B2 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 2A is independently -H or -R 2AA; - R 2AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 2B is independently -H or -R 2BB; - R 2BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 3A is independently -H or -R 3AA; - R 3AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 3B is independently -H or -R 3BB; - R 3BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 4A is independently -H or -R 4AA; - R 4AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 4B is independently -H or -R 4BB; and - R 4BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl. - R 1A1 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 1A2 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 1B1 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 1B2 is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 2A is independently -H or -R 2AA; - R 2AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 2B is independently -H or -R 2BB; - R 2BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 3A is independently -H or -R 3AA; - R 3AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 3B is independently -H or -R 3BB; - R 3BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 4A is independently -H or -R 4AA; - R 4AA is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl; - R 4B is independently -H or -R 4BB; and - R 4BB is independently C 1-4 alkyl; C 2-4 alkenyl; halogenated C 1-4 alkyl; C 5-10 aryl; halogenated C 5-10 aryl; C 5-10 aryl-C 1-4 alkyl; or halogenated C 5-10 aryl-C 1-4 alkyl.