scholarly journals Continuous-Flow Biocatalytic Process for the Synthesis of the Best Stereoisomers of the Commercial Fragrances Leather Cyclohexanol (4-Isopropylcyclohexanol) and Woody Acetate (4-(Tert-Butyl)Cyclohexyl Acetate)

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 102 ◽  
Author(s):  
Francesca Tentori ◽  
Elisabetta Brenna ◽  
Michele Crotti ◽  
Giuseppe Pedrocchi-Fantoni ◽  
Maria Chiara Ghezzi ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Synthetic Approach ◽  
Flow Process ◽  
Tert Butyl ◽  
Cis And Trans Isomers ◽  
Potent Odorants ◽  
Line Work ◽  
Cis And Trans ◽  
Work Up ◽  
Biocatalytic Process

Leather cyclohexanol (4-(isopropyl)cyclohexanol) and woody acetate (4-(tert-butyl)cyclohexyl acetate) are commercialized for functional perfumery applications as mixtures of cis- and trans-isomers. The cis-isomers are more potent odorants than the corresponding trans counterparts, but they are the less favoured products in most of the classical synthetic routes. Known stereoselective routes to cis-4-alkylcyclohexanols are characterized by a high environmental burden and/or troublesome reaction work-up. In this work, we examine the use of commercial alcohol dehydrogenases (ADHs) to produce cis-4-alkylcyclohexanols, including the two derivatives with isopropyl and tert-butyl substituents, by the stereoselective reduction of the corresponding ketones. High conversions and diastereoisomeric excess values were achieved with five of the eighteen tested ADHs. To complete the synthetic approach to woody acetate, Candida antarctica A (CALA) was employed as a catalyst for the enzymatic acetylation of cis-4-(tert-butyl)cyclohexanol. In order to provide a technological upgrade to the production of the most odorous isomers of the two commercial fragrances, we designed a continuous-flow process based on the combination of in-line enzymatic steps with in-line work-up, effectively providing samples of cis-leather cyclohexanol and cis-woody acetate with high diastereoisomeric purity.

cis/trans Isomers of Dimeric Dialkylaluminum and Dialkylgallium Hydrazides

2008 ◽  
Vol 63 (10) ◽  
pp. 1149-1154 ◽  
Author(s):  
Werner Uhl ◽  
Andreas Vogelpohl
Keyword(s):  
Solid State ◽  
Equilibrium Mixture ◽  
Trans Configuration ◽  
Trans Isomers ◽  
Tert Butyl ◽  
Hydrazine Derivatives ◽  
Piperidine Derivative ◽  
Cis And Trans Isomers ◽  
Gallium Hydride ◽  
Cis And Trans

AbstractThe reaction of diethylaluminum hydride with the hydrazine derivatives 1-aminopyrrole and 1- aminopiperidine afforded the corresponding dialkylaluminum hydrazides (1 and 2) by the release of elemental hydrogen. Both products are dimeric in the solid state. While 1 adopts a cis arrangement of the pyrrole groups, a trans configuration was determined for the piperidine compound 2. Only 1 gives an equilibrium mixture of cis and trans isomers in solution. Similar compounds (3 and 4) were obtained by the treatment of the same hydrazines with di(tert-butyl)gallium hydride. Both products exhibit the trans configuration in the solid state, but interestingly only the piperidine derivative 4 shows a cis/trans equilibrium in solution.

New synthesis of tetraazachlorins and tetraazabacteriochlorins by Diels–Alder reaction of tetraazaporphine

2000 ◽  
Vol 04 (05) ◽  
pp. 525-531 ◽  
Author(s):  
ELENA A. MAKAROVA ◽  
GALINA V. KOROLYOVA ◽  
OLEG L. TOK ◽  
EVGENY A. LUKYANETS
Keyword(s):  
Electronic Absorption Spectra ◽  
Analysis Data ◽  
Alder Reaction ◽  
Diels Alder ◽  
Elemental Analysis Data ◽  
Tert Butyl ◽  
H Nmr ◽  
Diels Alder Reaction ◽  
Cis And Trans Isomers ◽  
Cis And Trans

The use of the Diels–Alder reaction of unsubstituted tetraazaporphine as dienophile with some dienes of the anthracene series for the synthesis of novel substituted tetraazachlorins, tetraazabacteriochlorins and tetraazaisobacteriochlorins is reported. The condensation of tetraazaporphine with anthracene, 9,10-dimethyl- or 2,6-di(tert-butyl)anthracene in boiling chlorobenzene gives novel dibenzobarreleno-substituted tetraazachlorins 3–5 in yields of up to 71%. When AlCl3 was used as catalyst in the reaction of tetraazaporphine with 2,6-di(tert-butyl) anthracene, the corresponding cis- and trans-dibenzobarreleno-substituted tetraazabacteriochlorins 6a and 6b were obtained. The reaction of tetraazaporphine with the more active diene 2,3-benzanthracene at 130°C gives mainly benzonaphtho[2,3-b]barreleno-substituted tetraazachlorin 7, while the same reaction conducted at 220°C led to a mixture of cis- and trans isomers of tetraazabacteriochlorins 8a and 8b and tetraazaisobacteriochlorins 9a and 9b. The products were characterized using elemental analysis data and mass, 1H NMR and visible spectra. The effect of hydrogenation of one or two double bonds of the tetraazaporphine macrocycle on the electronic absorption spectra is discussed.

Radical-Initiated Hydrosilylation-Cyclization Reactions of Bis(vinyldimethylsilyl) Compounds, CH2=CH(CH3)2SiXSi(CH3)2CH=CH2 (X = O, CH2, NH, NCH3, NSi(CH3)3

1994 ◽  
Vol 49 (12) ◽  
pp. 1818-1826 ◽  
Author(s):  
Dietmar Seyferth ◽  
Holger Friedrich ◽  
Shane W. Krska
Keyword(s):  
Membered Ring ◽  
Trans Isomers ◽  
Cyclization Reactions ◽  
Tert Butyl ◽  
Cis And Trans Isomers ◽  
Butyl Peroxide ◽  
Cis And Trans

The di-tert-butyl peroxide-initiated reactions of triethyl- and tri-n-propylsilane with bis-(vinyldim ethylsilyl) compounds, CH2=CH(CH3)2SiXSi(CH3)2CH=CH2(X-O,CH2, NH,NCH3 and NSiMe3) resulted in hydrosilylation-cyclization to give mixtures of trialkylsilylm ethyl-substituted disilacyclohexanes and trialkylsilylm ethyl-substituted disilacyclopentanes. The ratio of six-membered to five-membered ring products obtained is dependent on the linking group X and decreased in the order X=O>CH2>NH>NCH3. For X = NSiMe3 only a mixture of the cis and trans isomers of the five-membered ring product was obtained.

scholarly journals Identification of Anthocyanin Compounds in Butterfly Pea Flowers (Clitoria ternatea L.) by Ultra Performance Liquid Chromatography/Ultraviolet Coupled to Mass Spectrometry

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4539
Author(s):  
Nguyen Minh Thuy ◽  
Vo Minh ◽  
Tran Ben ◽  
My Tuyen Thi Nguyen ◽  
Ho Ha ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Ultra Performance Liquid Chromatography ◽  
Negative Ion ◽  
Trans Isomers ◽  
Clitoria Ternatea ◽  
Flower Extract ◽  
Cis And Trans Isomers ◽  
Butterfly Pea ◽  
Cis And Trans

Butterfly pea flower have great sensory attraction, but they have not yet been used widely in Vietnam. Extracts of butterfly pea flowers can be used conveniently as a natural blue colorant for food products. In this study, the identification of anthocyanin compounds in butterfly pea flowers was performed by UPLC coupled with a UV and Mass spectrometer instrument. Positive and negative ion electrospray MS/MS chromatograms and spectra of the anthocyanin compounds were determined. By analyzing the chromatograms and spectra for each ion, five anthocyanins were identified in the butterfly pea flower extract; these were delphinidin-3-(6”‐p-coumaroyl)-rutinoside, cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl) glucose in both cis- and trans- isomers, cyanidin-3-(p-coumaroyl-glucoside) and delphinidin-3-pyranoside. Additionally, based on their intensity, it was determined that cyanidin-3-(p-coumaroyl-glucoside) was the most abundant anthocyanin, followed by cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl-glucoside), delphinidin-3-(6”-p-coumaroyl)-rutinoside and delphinidin-3-pyranoside. In this study, cyanidin derivatives were discovered in butterfly pea flower extract, where these compounds had not been detected in previous studies.

A Continuous Flow Process for LSN647712 via Double Organometallic Additions to Dimethylcarbamyl Chloride

2021 ◽  
Author(s):  
Hui Li ◽  
Jillian W. Sheeran ◽  
David Kouvchinov ◽  
Andrew M. Clausen ◽  
Ian T. Crouch ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Process ◽  
Continuous Flow Process
Sign in / Sign up

Export Citation Format

Share Document