The Prins reaction involves the addition of alkene to formaldehyde. Prins performed the first comprehensive study on the sulfuric acid-catalyzed reactions with formaldehyde of various alkenes such as styrene, pinene, camphene.
The reaction is catalyzed by a variety of protic and Lewis acids such as H2SO4, HCl, HOCl, HNO3, p-TsOH, BF3, AlCl3, ZnCl2, TiCl4.
The olefin-aldehyde condensation. The Prins reaction. Arundale, E., Mikeska, L. A. Chem. Rev. 1952, 51, 505-555.