adjective. Describing a molecular rearrangement in which a covalent single bond is formed between the ends of a fully conjugated system resulting in a cyclic compound with one fewer double bonds

"I began to look at all kinds of organic transformations, and so I was prepared when in the Spring of 1964 R.B. Woodward asked me some questions about what subsequently came to be called electrocyclic reactions."

electrolytic  electrophilic