76686-09-4Relevant articles and documents
β-hydroxysulfoxides as chiral cyclic ketone equivalents: Enantioselective synthesis of polysubstituted cyclohexanones, cyclohexenones and cyclohexenediones
Carreno, M. Carmen,Perez-Gonzalez, Manuel,Ribagorda, Maria,Somoza, Alvaro,Urbano, Antonio
, p. 3052 - 3053 (2007/10/03)
The β-hydroxysulfoxide moiety, after oxidation to sulfone, acts as a masked carbonyl group in a cyclic system, opening an easy access to differently substituted enantiomerically pure cyclic ketones by means of aluminium-mediated conjugate additions, stereoselective reductions and elimination by retrocondensation in basic medium.
Synthesis of (R)- and (S)-4-hydroxyisophorone by ruthenium-catalyzed asymmetric transfer hydrogenation of ketoisophorone
Hennig, Michael,Puentener, Kurt,Scalone, Michelangelo
, p. 1849 - 1858 (2007/10/03)
The first synthesis of (R)- and (S)-4-hydroxyisophorone by catalytic transfer hydrogenation of ketoisophorone is reported. Ruthenium catalysts containing commercially available chiral amino alcohols afforded 4-hydroxyisophorone in up to 97% selectivity an
Hydrolase-catalyzed preparation of (R)- and (S)-4-hydroxy-2,6,6- trimethyl-2-cyclohexen-1-ones (phorenols), the key synthetic intermediates for abscisic acid
Kiyota, Hiromasa,Nakabayashi, Miho,Oritani, Takayuki
, p. 3811 - 3817 (2007/10/03)
Preparation of both the enantiomers of 4-hydroxy-2,6,6-trimethyl-2- cyclohexen-1-one (phorenol), which are versatile synthetic intermediates for abscisic acid and carotenoids, was achieved by hydrolase-catalyzed hydrolysis of the corresponding chloroaceta
The Synthesis of Optically Active Enriched (+)-(6R)-α-Ionone
Pfander, Hanspeter,Semadeni, Pascal A.
, p. 145 - 151 (2007/10/02)
Starting with the readily available (-)-(S)-4-hydroxy-2,6,6-trimethylcyclohex-2-en-1-one (2) an optically active enriched sample of (+)-(6R)-α-ionone (1) (85percent enantiomeric excess) was synthesized.
Enzymatic Preparation of Chiral 4-Hydroxy-2,2-dimethyl-1-cyclohexanone as a Chiral Building Block
Yamamoto, Hiroshi,Oritani, Takayuki,Koga, Hideo,Horiuchi, Tadao,Yamashita, Kyohei
, p. 1915 - 1921 (2007/10/02)
(S)-4-Hydroxy-2,2-dimethyl-1-cyclohexanone (1a) was prepared by two enzymatic methods. 1,4-Cyclohexanediol was converted to monoacetal (11) via (+/-)-1a.Enzymatic reduction of 11 by baker's yeast gave (S)-1 of almost 100 percent e.e.Direct hydroxylation of 2,2-dimethyl-1-cyclohexanone (14) by P-450 camphor monooxygenase of the cloned genes of Pseudomonas putida PpG1 gave (S)-1a of almost 100 percent e.e., too.According to Mitsunobu's method, SN-2 inversion of (S)-1 gave (R)-1.
Microbial Conversion of 4-Oxoisophorone by Thermophile, Thermomonospora curvata
Hori, Nobuaki,Hieda, Tadaharu,Mikami, Yoichi
, p. 123 - 130 (2007/10/02)
Thermomonospora curvata IFO 12384 was selected from many thermophiles tested as a strain capable of converting 2,6,6-trimethyl-2-cyclohexene-1,4-dione (4-oxoisophorone) into (6R)-2,2,6-trimethyl-1,4-cyclohexadione ((3R)-dihydro-4-oxoisophorone) efficiently.The other conversion products were also isolated and identified by spectrometry.Based on the results of experiments with a degradation sequence, a conversion pathway for 4-oxoisophorone by this thermophile is proposed.The effects of nutritional conditions, temperature, initial pH and the concentration of the substrate on the conversion were examined.Under the optimal conditions, the conversion ratio of 4-oxoisophorone to (3R)-dihydro-4-oxoisophorone was over 95percent.The production rate of (3R)-dihydro-4-oxoisophorone was 86 mg per 1 g of dry cells per hr.
Technische Verfahren zur Synthese von Carotinoiden und verwandten Verbindungen aus Oxo-isophoron. I. Modifizierung der Kienzle-Mayer-Synthese von (3S,3'S)-Astaxanthin
Widmer, Erich,Zell, Reinhard,Lukac, Teodor,Casadei, Marco,Schoenholzer, Peter,Broger, Emil A.
, p. 2405 - 2418 (2007/10/02)
An efficient synthesis of (3S,3'S)-astaxanthin (1a) in high yield and optical purity starting from (4R,6R)-4-hydroxy-2,2,6-trimethylcyclohexanone (4) is reported.The absolute configuration of 1a, previously derived from ORD. data, has been confirmed by X-ray analysis of 5, a derivate of 6-oxo-isophorone (2).The key features of the improved synthesis are the two-step conversion of 4 to the key intermediate (4S)-2,6,6-trimethyl-4-hydroxy-2-cyclohexen-1-one (14), a new method for the partial reduction of the sterically hindered triple bond of (S)-6-hydroxy-3-(5-hydroxy-3-methyl-3-penten-1-ynyl)-2,4,4-trimethyl-2-cyclohexen-1-one (32), and Wittig olefination of the dialdehyde 1,6-dimethyl-1,3,5-octatrienedial (38) using phosphonium salt 37 with a free hydroxyl group.
153. Synthese von optisch aktiven, natuerlichen Carotinoiden und strukturell verwandten Naturprodukten. IV. Synthese von (3R,3'R,6'R)-Lutein
Mayer, Hans,Ruettimann, August
, p. 1451 - 1455 (2007/10/02)
The synthesis of (3R,3'R,6'R)-lutein (19) according to the building principle C25+C15=C40 is reported utilizing (R)-4-hydroxy-2,6,6-trimethyl-2-cyclohexen-1-one (4) as a readily available key intermediate.
