Poly(4-vinylpyridinium) hydrogen sulfate solid acid was found to be efficient catalyst for preparation of 1,1-diacetate at room temperature and neat condition. Deprotection of the resulting 1,1-diacetates was achieved using the same catalyst in methanol solvent. This new method consistently has the advantage of excellent yields and short reaction times. Further, the catalyst can be reused and recovered for several times but they will be less active. (C) 2011 Elsevier B.V. All rights reserved.