text: One common application of the Thorpe-Ingold effect is in the acceleration of these reactions by the addition of a geminal-dimethyl group to the reactant molecule.
full_question: One common application of the Thorpe-Ingold effect is in the acceleration of these reactions by the addition of a geminal-dimethyl group to the reactant molecule. Concerted examples of these reactions that also have negative entropies of activation can have conrotatory or disrotatory transition states. A radical-rearrangement of an enediyne is one type of this reaction named for Bergmann. All exo-tet and exo-trig varieties of these reactions are favored, according to Baldwin's rules. When intramolecular, these reactions are fastest when reacting groups are five carbons away. One example of this type of reaction is a condensation named for Dieckmann which forms beta-ketoesters. For 10 points, name these reactions that form rings from carbon chains.
first_sentence: One common application of the Thorpe-Ingold effect is in the acceleration of these reactions by the addition of a geminal-dimethyl group to the reactant molecule.
raw_answer: cyclizations [accept ring-forming reaction before mention; accept Bergmann cyclization; anti-prompt on "lactonization", "electrocyclization", "cycloaddition", or "pericyclic reaction