One pot synthesis of menthol from (¡À)-citronellal on nickel sulfated zirconia catalysts

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• 作者：Cé ; sar Barrales  ; Corté ; s ; Victoria Tamayo  ; Galvá ; n ; Smid Santiago  ; Pedro ; Tomá ; s Viveros  ; Garc&iacute ; a  ; ;   ; ^{tvig@xanum.uam.mx}
• 关键词：Nickel catalysts ; Menthol ; Citronellal ; Sulfated zirconia ; Cyclization ; Isopulegol
• 刊名：Catalysis Today
• 出版年：2011
• 出版时间：25 August 2011
• 年：2011
• 卷：172
• 期：1
• 页码：21-26
• 全文大小：731 K

文摘

The one-pot synthesis of menthol from (¡À)-citronellal was carried out using two catalysts: nickel supported on sol¨Cgel sulfated zirconia (Ni/ZrS) and nickel added during the synthesis of sulfated zirconia (NiZrS). The supported catalyst was prepared by impregnation of nickel on the sulfated zirconia support, whereas NiZrS was prepared by the co-gellation of nickel and the sulfated zirconia by the sol¨Cgel method. Two sets of catalytic tests were carried out. In both tests the catalysts were previously treated in He stream. First, the liquid phase cyclization of (¡À)-citronellal was carried out with both ZrS and NiZrS catalysts. The results showed that both ZrS and NiZrS catalysts are highly active and selective towards isopulegols (100 % of selectivity) and highly stereoselective towards (¡À)-isopulegol (?0 % of selectivity). A second reaction test was the synthesis of menthol. The catalysts were evaluated in a batch reactor at 1.4 MPa of H₂ and 100 ¡ãC. The results showed that the catalysts allow to obtain a high catalytic activity and selectivity towards stereoisomers of menthol (100 % selectivity of menthols) and a high selectivity towards (?-menthol.