Under CO atmosphere, a glyme solution of PtCl4 forms, between 80 and 120 degreesC, a carbonyl compound that promotes hydration of internal and terminal alkynes to give aldehyde-free ketones. The catalytic process depends strongly on the electronic and steric nature of the alkynes. Part of the carbonyl functions of the catalyst can be replaced by phosphine ligands, including chiral DIOP and polystyrene-bound diphenylphosphine. Upon entrapment of the platinum compound in a silica sol-gel matrix, it reacts as a partially recyclable catalyst. (C) 2002 Elsevier Science B.V. All rights reserved.