Efficient and Selective Oxidative Deprotection of Tetrahydropyranyl Ethers, Ethylene Acetals and Ketals with Silver and Sodium Bromates in the Presence of Aluminum Chloride
Chemoselective trimethylsilylation and tetrahydropyranylation of benzylic and primary and secondary aliphatic alcohols proceed efficiently in the presence of 1,3-dibromo-5,5-dimethylhydantoin (DBH) under mild and completely heterogeneous reaction conditions in excellent yields.
Selective, Convenient and Efficient Deprotection of Trimethylsilyl and Tetrahydropyranyl Ethers, Ethylene Acetals and Ketals with Oxone under Non-aqueous Conditions
An efficient and selective method for the deprotection of trimethylsilyl (TMS) and tetrahydropyranyl (THP) ethers, ethylene acetals and ketals to their corresponding alcohols and carbonyl compounds using oxone in refluxing acetonitrile is described. Excellent chemoselectivity of this method makes it a useful and practical procedure in organic synthesis.
AN EFFICIENT METHOD FOR SELECTIVE DEPROTECTION OF TRIMETHYLSILYL ETHERS, TETRAHYDROPYRANYL ETHERS, ETHYLENE ACETALS, AND KETALS UNDER MICROWAVE IRRADIATION
作者:A. R. Hajipour、S. E. Mallakpour、I. Mohammadpoor-Baltork、S. Khoee
DOI:10.1081/scc-120002408
日期:2002.1.1
[2.2.2]octane dichromate (BAABOD) is a useful reagent for the selective cleavage of trimethylsilyl ethers, tetrahydropyranyl ethers, ethylene acetals and ketals to their corresponding alcohols, aldehydes and ketones. This method is very simple and efficient and the reaction has been carried out under microwave irradiation.
Silica Triflate as a New, Mild and Efficient Catalyst for Tetrahydropyranylation of Alcohols and Deprotection of Tetrahydropyranyl Ethers
作者:F. Shirini、K. Marjani、H. Taherpour Nahzomi
DOI:10.1080/10426500701407839
日期:2007.7.19
Silica triflate, a new stable derivative of silica gel, is easily prepared by the reaction of silica gel with trifluoromethanesulfonyl chloride. Silica triflate acts as a highly effective and reusable catalyst for tetrahydropyranylation of alcohols and deprotection of tetrahydropyranylethers under mild and completely heterogeneous reaction conditions.
The synthetic utility of potassium dichromate in the presence of Lewis acids under solid phase conditions is described. This reagent efficiently oxidizes alcohols, acyloins, oximes and semicarbazones to their corresponding carbonyl compounds, while trimethylsilyl and tetrahydropyranylethers, ethylene acetals and ketals undergo oxidative deprotection to produce carbonyl compounds efficiently.