title: The dimethoxyphenylbenzyl protecting group: an alternative to the p-methoxybenzyl group for protection of carbohydrates.
abstract: A reliable reagent system for the cleavage of 4-(3,4-dimethoxyphenyl)benzyl (DMPBn) ethers under acidic conditions has been established. Treatment of DMPBn-protected mono- and pseudodisaccharides with TFA in anhydrous CH2Cl2 and 3,4-(methylenedioxy)toluene as a cation scavenger resulted in the selective cleavage of the DMPBn ether giving the corresponding deprotected products in moderate to high yields. Examples are reported which show that allyl, benzyl, and p-bromobenzyl ethers, esters, and glycosidic linkages are stable to these reaction conditions. The selective cleavage of allyl, p-bromobenzyl, and PMB ethers in protected carbohydrates containing DMPBn ethers are also demonstrated. This work establishes the 4-(3,4-dimethoxyphenyl)benzyl ether as an effective and robust alternative to p-methoxybenzyl as a protecting group for alcohols.
authors.affiliation: University of Otago, PO Box 56, Dunedin, New Zealand.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Rankin
authors.forename: Isobel
authors.initials: I
authors.lastname: Maxwell-Cameron
authors.forename: Gavin F
authors.initials: GF
authors.lastname: Painter
authors.forename: David S
authors.initials: DS
authors.lastname: Larsen
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis* / Q000737:chemistry; D001593:Benzyl Compounds / Q000737:chemistry*; D002241:Carbohydrates / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: C584177:4-(3,4-dimethoxyphenyl)benzyl ether; D000438:Alcohols; D001593:Benzyl Compounds; D002241:Carbohydrates; D004987:Ethers