Zeolite catalyzed selective deprotection of di- and tri-O-isopropylidene sugar acetals.
H-Beta zeolite, a microporous solid acid, is demonstrated to be an efficient catalyst for the selective deprotection of cyclic as well as acyclic O-isopropylidene sugar acetals derived from d-glucose, D-xylose, D-mannose, and D-mannitol in aqueous MeOH at room temperature. A notable observation is the conversion of d-mannitol triacetonide into 1,2:3,4-di-O-isopropylidene-D-mannitol (48%) and 3,4-O-isopropylidene-D-mannitol (36%) brought about in 6h by H-beta zeolite and the non-occurrence of any hydrolysis in the case of H-ZSM-5 catalyzed reaction in 24h under the same conditions.
Bhaskar
Pallooru Muni
PM
Department of Chemistry, Indian Institute of Technology Madras, Chennai, India.
Mathiselvam
Manoharan
M
Loganathan
Duraikkannu
D
D000080:Acetals / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry; D002384:Catalysis; D017641:Zeolites / Q000737:chemistry*
D000080:Acetals; D000475:Alkenes; D017641:Zeolites; C013658:propylene