Solvent-Promoted E2 Reaction Competing with SN2 Reaction and Stepwise Solvolytic Elimination and Substitution Reactions

Solvolysis of 9-(1-X-ethyl)fluorene (1-X, X = I, Br, Cl, OTs, or OBs) in 25 vol % acetonitrile in water gives the elimination products 9-(1-ethylidene)fluorene (3) and 9-vinylfluorene (2) and the substitution products 9-(1-hydroxyethyl)fluorene (1-OH) an