Synthesis of (S)-2-Hydroxy-β-ionone, Employing (S)-3-Hydroxy-2,2-dimethylcyclohexanone as the Chiral Starting Material

Baker's yeast mediated transformations in organic chemistry

“…(The optical rotations reported for enantiomerically pure 179 are controversial. 143,144) It is of interest to note that (S)-2,2-dimethyl-3hydroxycyclohexane ( 179) is obtained in lower ee with DMF/H20 (1:38) as the solvent for this reaction. 145 179 is a valuable intermediate and has been used both for the synthesis of (S)-2-hydroxy-/3-ionon (isolated as a metabolite of /3-ionone from the broth of Aspergillus niger and known to have an improving effect on tobacco flavor146) and for the synthesis of glycinoaclepin A (showing a significant hatch-stimulating activity for the soybean cyst nematode);145 it has also been used for the synthesis of (-)-polygodial147-a hot-tasting sesquiterpene from Polygonum hydropiper,148,149 which possesses antifeedant activity against African crop insects such as the army worm Spodoptera exempla.150 Finally, 179 has been used for the synthesis151 of the monoterpenoid karahana compounds of 6-oxabicyclo-[3. achieved as in the case of the fiveor six-membered rings and resulted in high recovery rates.…”

Yeast‐Mediated Stereoselective Synthesis

“…Hence, the addition of activators has been suggested [191]. These "activators" (most often α,β-unsaturated alcohols, ketones, or nitriles) seem to act as suicide substrates for several oxidoreductases [192,193], whereas, for the reduction of cyclopentanoid 1,3-diketones, stereoselectivity was high, and most often [194] low selectivity was observed for cyclohexanoid 1,3-diketones [184,[194][195][196][197].…”

Synthesis of (4aR, 10aS)-(—)-8-Methoxy-1,1,4a-trimethyl-2-oxo-1,2,3,4,4a,9,10,10a-octahydrophenanthrene, an Optically Active Intermediate for the Synthesis of Diterpenes

“…3b (1.8 g, 91 % from 3a), bp 80,..., 84°C/0. 5 To a stirred solution of bromomethyltriphenylphosphonium bromide (22.9 g) in tetrahydrofuran (THF, 100 ml), a solution of potassium tbutoxide (l5.6g) in THF (50ml) was added under argon at -68°C. After stirring for 30 min, a solution of o-anisaldehyde (7.1 g) in THF (20 ml) was added to the mixture.…”