Silica‐Gel‐Supported Aluminium Chloride: A Stable, Efficient, Selective, and Reusable Catalyst for Tetrahydropyranylation of Alcohols and Phenols
作者:Kaveh Parvanak Borujeni
DOI:10.1080/00397910600764725
日期:2006.9
Abstract A simple, effective, and highly chemoselective method to form 2‐tetrahydropyranyl ethers of alcohols and phenols in the presence of silica‐gel‐supported aluminium chloride as a heterogeneous Lewisacidcatalyst is described. The catalyst can be easily recovered and reused without appreciable change in its efficiency.
Polystyrenesupported TiCl4 (Ps‐TiCl4) and polystyrenesupported FeCl3 (Ps‐FeCl3) were prepared by coordinating Lewisacids with polystyrene. The catalysts were characterized by TGA, BET, SEM, IR and pyridine‐adsorbed IR. The loading of Ps‐TiCl4 and Ps‐FeCl3 were 0.35 and 0.3 mmol·g−1 respectively. Both catalysts were found to be efficient for the tetrahydropyranylation and detetrahydropyranylation
Mild and efficient tetrahydropyranylation and deprotection of alcohols catalyzed by heteropoly acids
作者:Árpád Molnár、Tímea Beregszászi
DOI:10.1016/0040-4039(96)01965-x
日期:1996.11
A simple, mild and effective method to form 2-tetrahydropyranyl ethers of alcohols and phenol and the removal of this protective group in the presence of heteropoly acids as catalysts are described.
Photoinduced transformations. Part 73. Transformations of five- (and six-) membered cyclic alcohols into five- (and six-) membered cyclic ethers - a new method of a two-step transformation of hydroxy steroids into oxasteroids