77-42-9Relevant academic research and scientific papers
The synthesis of (Z)-trisubstituted allylic alcohols by the selective 1,4-hydrogenation of dienol esters: Improved synthesis of (-)-β-santalol
Fehr, Charles,Magpantay, Iris,Vuagnoux, Magali,Dupau, Philippe
experimental part, p. 1257 - 1260 (2011/04/16)
(E)-Trisubstituted allylic alcohols are commonly prepared from the corresponding (E)-enals, themselves readily accessible by a simple aldol condensation reaction. We demonstrate that these very same (E)-enals can be converted into (Z)-trisubstituted allylic acetates (and thus alcohols) by a ruthenium-catalyzed 1,4-hydrogenation of the corresponding dienol acetates. This simple solution to a long-lasting problem was applied to an industrially feasible synthesis of (-)-β-santalol.
Radical cyclizations leading to the bicyclo[2.2.1]heptane framework: A new radical approach to (±)-(Z)-β-santalol
Pianowski, Zbigniew,Rupnicki, Leszek,Cmoch, Piotr,Staliński, Krzysztof
, p. 900 - 904 (2007/10/03)
Tandem radical cyclizations of acyclic iodides, including [3-(2-iodoethyl)-6,10-dimethyl-undeca-5,9-dien-1-ynyl]-dimethylphenylsilane lead in good yields to bicyclo[2.2.1]heptane derivatives. The cascade relies on two sequential radical-mediated 5-exo-cyclizations. The radical approach is illustrated with the total synthesis of racemic-(Z)-β-santalol. The results are remarkable, two fused rings and one stereogenic center are formed in a single operation. A new 'coordinated' hydride appeared to be useful in the cascade.
Total Syntheses, Optical Rotations and Fragrance Properties of Sandalwood Constituents: (-)-(Z)- and (-)-(E)-β-Santalol and Their Enantiomers, ent-β-Santalene
Krotz, Achim,Helmchen, Guenter
, p. 601 - 610 (2007/10/02)
Enantiomerically pure 5-norbornene-2-carboxylic acids 4, obtained by asymmetric Diels-Alder additions, were oxidatively degraded to (+)- and (-)-2-norbornanone and (+)- and (-)-3-methyl-2-norbornanone which were converted into the title compounds by stereoselective alkylations, subsequent cis- and trans-selective Wittig reactions and reductions.Precise optical rotations were determined for (Z)- and (E)-β-santalol (1 and 2) and β-santalene (3a) which were obtained by total synthesis and, in addition, by isolation from East Indian sandalwood oil. - Key Words: Sandalwood oil / Fragrances / Stereoselective synthesis / β-Santalene, pure, isolation / Enantiomers, fragrance properties
Total Syntheses of Sandalwood Fragrances: (Z)- and (E)-β-Santalol and Their Enantiomers, ent-β-Santalene
Krotz, Achim,Helmchen, Guenter
, p. 537 - 540 (2007/10/02)
Via asymmetric Diels-Alder reactions, large scale preparations of enantiomerically pure norbornane-2-carboxylic acids were carried out.Oxidative degradation furnished 2-norbornanone and 3-methyl-2-norbornanone which gave the title compounds via stereoselective alkylations, subsequent Wittig reactions and reductions.
Cyclopropane Ring Cleavage in the α-Santal Series, I. - The Absolute Configurations of (-)-β-Santalol, (+)-epi-β-Santalol, and (E)-(-)-β-Santalol
Brunke, Ernst-Joachim,Boehme, Andreas,Struwe, Hartmut
, p. 1105 - 1110 (2007/10/02)
Cyclopropane cleavage of (+)-α-santalyl acetate (1b) by treatment firstly with HCl/CHCl3 at -50 deg C and secondly with basic alumina resulted in (-)-β-santalyl acetate (2b) and (+)-epi-β-santalyl acetate (3b).The identity with 2b, 3b, isolated from east indian sandalwood oil, was demonstrated by 1H-, 13C-NMR, and ORD spectra.This result defines the absolute configurations of the β-santalols 2a, 3a, and 4a.
Stereoselective Syntheses of (+/-)-epi-β-Santalene and (+/-)-epi-β-Santalol
Snowden, Roger L.,Sonnay, Philippe,Ohloff, Guenther
, p. 25 - 32 (2007/10/02)
Stereoselective syntheses of (+/-)-epi-β-santalene (1) and (+/-)-epi-β-santalol (2), minor constituents of East Indian sandalwood oil, are described.The starting material for both syntheses is the tricyclic hemiacetal 4, readily accessible in two steps from norbornene.
East Indian Sandalwood Oil. 2. Stereoselective Synthesis of (+/-)-Epi-β-santalene and (+/-)-Epi-β-santalol
Christenson, Philip A.,Willis, Brian J.
, p. 3068 - 3072 (2007/10/02)
Acid-catalyzed rearrangement of γ-lactone 6 in the presence of acetonitrile provides a mixture of amide acids, which are readily separated as their ethyl esters 18-20.The major product 18, when subjected to fragmentation, provides esters 21 and 22 (92percent and 8percent, respectively).The structure of 21 has been confirmed by its conversion, via aldehyde 23, to (+/-)-epi-β-santalene (8).Similarly, the structure of 22 has been confirmed by its conversion to (+/-)-α-santalene (3). (+/-)-Epi-cis-β-santalol (9), (+/-)-epi-trans-β-santalol (10), and (+/-)-dihydroepi-β-santalol (11) have also been prepared via aldehyd 23.
