A fast and practical approach to tetrahydropyranylation and depyranylation of alcohols using indium triflate
摘要:
Indium triflate-mediated tetrahydropyranylation of alcohols in dichloromethane and depyranylation of these products in aqueous methanol utilizing the same reagent but different molar ratio is described. In addition, indium triflate-promoted conversion of tetrahydropyran ethers to their corresponding acetates has also been described. (C) 2002 Elsevier Science Ltd. All rights reserved.
ABSTRACT The efficient and rapid esterification of alcohols and phenols in aceticanhydride was achieved by tin(IV) tetraphenylporphyrin perchlorate [SnIV (tpp) (ClO4)2] as catalyst in high yields. SnIV (tpp) (ClO4)2 showed highly catalytic activity on the acetylation reaction.
This invention relates to a range of alpha substituted 2-benzyl substituted imidazole compounds and pharmaceutically acceptable salts and solvates thereof, to compositions comprising such compounds, processes for their synthesis and their use as parasiticides.
acetolysis rates of 2-arylethyl tosylates were determined for a series of aryl substituents. The non-linear substituent effect was reasonably accounted for on the basis of two linear LArSR relationships; one for the aryl-assisted (FkΔ) and one for the unassisted (ks) processes, respectively. A precise dissection of the apparent substituent effect into individual effects for both processes was achieved
ZrCl4 as a mild and efficient catalyst for the one-pot conversion of TBS and THP ethers to acetates
作者:Ch.Sanjeeva Reddy、G Smitha、S Chandrasekhar
DOI:10.1016/s0040-4039(03)01078-5
日期:2003.6
A mild, efficient and chemoselective method has been developed for the direct transformation of tert-butyldimethylsilyl and tetrahydropyranyl protected alcohols into the corresponding acetates with acetic anhydride and zirconium(IV) chloride as the catalyst in acetonitrile, in a one-pot reaction with high yields and short reaction times. This method has been applied to a variety of substrates. (C) 2003 Elsevier Science Ltd. All rights reserved.
El Zein,M. et al., Bulletin des Societes Chimiques Belges, 1978, vol. 87, p. 67 - 74