Oxidative Deprotection of Tetrahydropyranyl Ethers to Carbonyl Compounds with 4-(Dimethylamino)pyridinium and 2,2′-Bipyridinium Chlorochromates under Non-aqueous Conditions†

Clay Supported Bis(trimethylsilyl)chromate: Oxidative Deprotection of Tetrahydropyranyl Ethers under Solvent-Free Conditions using Microwaves

“…We examined various mineral supports such as clays, silica gel, or alumina and found that montmorillonite K-10 provides the best results in terms of formation of pure products. The yields are much higher than those reported for related reactions [18,19]. In the absence of support, the reaction is very slow, the yield is low, and the isolation of products from the ensuing residues is dif®cult.…”

“…The tetrahydropyranyl group is one of the most useful protective groups for alcohols in multi-step organic synthesis [1], and considerable efforts have been made for the development of new methods for their introduction and removal [2±17]. However, there are only few reports dealing with the direct oxidation of tetrahydropyranyl ethers to the corresponding carbonyl compounds [18,19]. Consequently, there is a need to develop and introduce new methods and reagents for this transformation.…”

Benzyltriphenylphosphonium Peroxodisulfate: A Mild and Inexpensive Reagent for Selective Oxidative Deprotection of Trimethylsilyl and Tetrahydropyranyl Ethers, Ethylene Acetals and Ketals under Non-Aqueous and Aprotic Conditions

“…24 Recently, we have introduced new methods for the oxidative deprotection of trimethylsilyl and tetrahydropyranyl ethers, ethylene acetals and ketals. [25][26][27] In continuation of our research in this area, we now report benzyltriphenylphosphonium peroxodisulfate as an efficient reagent for the conversion of TMS and THP ethers, ethylene acetals and ketals to their corresponding carbonyl compounds. For this purpose, first, we have studied the oxidative deprotection of 2-methoxybenzyltrimethylsilyl ether to 2-methoxybenzaldehyde with this reagent in common organic solvents such as MeCN, CH 2 Cl 2 , CHCl 3, THF and n-hexane.…”

An Efficient Method for Selective Deprotection of Trimethylsilyl Ethers, Tetrahydropyranyl Ethers, Ethylene Acetals, and Ketals Under Microwave Irradiation

“…Trimethylsilyl ethers, tetrahydropyranyl ethers, ethylene acetals were prepared according to described procedures, 15,16 All of the products were characterized by comparison of their spectral (IR, 1 H-NMR), TLC and physical data (melting and boiling point) with those of authentic samples. 5,12,20,[27][28][29] The reagent 1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane dichromate (3) was prepared according to described procedures.…”