CYCLIZATIONAND HYDROGENATION OF (+)-cITRONELLAL TO MENTHOLS OVER ZnBr2ANDNiCATALYSTSSUPPORTEDONy-A1203
| Main Author: | Perpustakaan UGM, i-lib |
|---|---|
| Format: | Article NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2010
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/28081/ http://i-lib.ugm.ac.id/jurnal/download.php?dataId=11144 |
Daftar Isi:
- ABSTRACT Two steps transformation of (+)-citronella/, cyclization and hydrogenation, on ZnBrfl-A/z03 and NVy-A/z03 catalyst have been realized with the selectivity to cyclization products (isopulegols) was vel}' high (yield up to -92.58%) over ZnBrfl-A/z03 under mild condition (90 DCand 1 atm nitrogen atmosphere) with high Br(IJnstedacid concentration, while at the same time vel}' low cyclization rates were achieved over NVy-A/z03 with low or no Br(IJnsted acidity, respectively. The highest cyclization rates were observed over NVZnBrfl-A/z03 under -mild condition (90 DCand 1 atm hydrogen atmosphere). The second step transfo.rmation towards cyclization products, hydrogenation to menthols, was performed with NVy-A/Z03 under hydrogen atmosphere. Surprisingly the one-step transformation of (+)-citronellal into menthols was investigated over NVy-A/z03 with yield -84% under hydrogen atmosphere (90 DC,1 atm) by exploiting the presence of acidic and hydrogenation sites on the catalyst surface. On the NVy-A/z03 catalyst it was found that the cyclization of (+)-citronellal to isopulegols occurs on the surface of the support. In the presence of the noble metal, the isopulegols are further hydrogenated to the menthols. Keywords: cyclization, hydrogenation, citronella/, isopulegol, menthol