P4VP-H₂SO₄-Catalyzed Chemoselective Protection of Aldehydes to Acylal Along with Deprotection Reactions

Abstract

Poly(4-vinylpyridine)-supported sulfuric acid is an excellent reusable heterogeneous catalyst for the chemoselective synthesis of 1,1-diacetates(acylal) from aldehydes in dichloromethane at room temperature within a few minutes. The protection of salicyaldehyde generated an anhydro-dimer as single product under similar reaction conditions. The catalyst is equally applicable for the deprotection of acylal in acetonitrile. The catalyst was prepared by the wet impregnation technique.

GRAPHICAL ABSTRACT

Keywords:

• Chemoselectivity
• 1,1-diacetates
• protection–deprotection
• reusable catalyst
• supported solid acid

Notes

^a All products were characterized by ¹H NMR, ¹³C NMR, FT-IR, and TLC comparison with authentic samples prepared by reported methods.

^b The reaction was carried out using a 1: 6 ratio of substrate and acetic anhydride.

^c The reaction was carried out using a 1:4 ratio of substrate and acetic anhydride.

^a Isolated yield.