has specified product has specified reactant has_part aldehyde tetrabromomethane butyllithium terminal acetylenic compound chain lengthening Corey-Fuchs reaction A homologation reaction of an aldehyde to yield a terminal alkyne. The reagents are tetrabromomethane, triphenylphosphine, butyllithium and water. RXNO RXNO:0000146 Ramirez-Corey-Fuchs reaction https://www.rsc.org/Merck-Index/reaction/r89/ https://www.wikidata.org/wiki/Q903573 Fritsch-Buttenberg-Wiechell rearrangement Corey-Fuchs terminal dibromoolefination