A Polymeric FeCl₃ Catalyst for Deprotection of Acetonides

acetonides - catalysis - diols

Significance

Highly chemoselective deprotection of diacetone sugars bearing various functional groups was achieved at room temperature for 30 minutes using poly(4-vinylpyridine)-supported ferric chloride (5 mol%) to give the corresponding terminal diols 2 in 87-94% yields (15 substrates). This method was found to be of good functional compatibility with acid-sensitive groups such as TBDMS, THP, OBn, OBz, and OAc. The polymeric catalyst was readily recycled without lenching of ferric chloride.

Comment

Several examples of protection/deprotection of 1,2-diols with acetonide using FeCl₃ (e.g., A. Fadel, R. Yefsah, J. Salaün Synthesis 1987, 37-39) have been reported so far.