نتایج جستجو برای: chiral non racemic menthol

تعداد نتایج: 1354057  

2012
Zhen-ju Jiang Qi He Zhen Li Zhou-yu Wang

In the title compound, C(14)H(17)NO, the piperidinone and piperidine rings both adopt a chair conformation. The chiral crystals were obtained from a racemic reaction product via spontaneous resolution.

Journal: :Angewandte Chemie 2013
Chong Liu Jian-Hua Xie Ya-Li Li Ji-Qiang Chen Qi-Lin Zhou

Chiral diols with three contiguous stereocenters were synthesized by a highly enantioselective ruthenium-catalyzed asymmetric hydrogenation of racemic α,α'-disubstituted cycloketones involving dynamic kinetic resolution. This new catalytic asymmetric method provides a concise route to the alkaloid (+)-γ-lycorane.

Journal: :Chemical communications 2009
Pandi Muthupandi Santosh Kumar Alamsetti Govindasamy Sekar

An efficient, economic and environmentally friendly enantioselective oxidation of racemic benzoins (alpha-hydroxy ketones) catalyzed by a chiral iron complex has been developed using molecular oxygen as a terminal oxidant with good selectivity and excellent enantiomeric excess.

Journal: :Chemical communications 2004
Asao Nakamura Tomohiro Sato Reiko Kuroda

Grinding a 1 : 1 enantiomeric mixture of chiral transition metal complex crystals and subsequent annealing afforded crystals of a racemic compound by diffusion and rearrangement of component molecules, without melting and without racemization of each enantiomeric species.

2012
Judith Rosenbloom Vaughan W Rees Kathleen Reid Jeannie Wong Taru Kinnunen

UNLABELLED BACKGROUND The question of whether mentholation of cigarettes enhances tobacco dependence has generated conflicting findings. Potential mediating factors in a putative relationship between menthol use and tobacco dependence may include race and gender. While an association between menthol use and dependence is mixed, research on the role of race solely among women smokers is scarc...

Journal: :Organic & biomolecular chemistry 2011
Joong-Suk Oh Kyung Il Kim Choong Eui Song

Catalytic dynamic kinetic resolution (DKR) of racemic azlactones with EtOD using squaramide-based dimeric cinchona alkaloid organocatalysts is shown to be a highly effective strategy for the preparation of enantiomerically pure α-deuterated chiral α-amino acids.

Journal: :Chemical communications 2007
Iain Coldham Jignesh J Patel Sophie Raimbault David T E Whittaker

Asymmetric substitution of 2-lithiopiperidines can be achieved by dynamic resolution; the organolithium is formed as a racemic mixture by proton abstraction (or tin-lithium exchange) and is resolved in the presence of a chiral ligand.

2011
Paul Kuhlich Franziska Emmerling Christian Piechotta Irene Nehls

Crystals of the title compound, C(18)H(26)O(2), were grown from ethyl acetate. Due to the racemic precursor, the title compound is also obtained as a racemate. Disorder was observed during structure refinement, originating from two possible half-chair conformations of the non-aromatic ring. The disorder was refined by introducing split positions in the cyclo-hexane ring regarding the two possib...

Journal: :Chemistry 2013
Hagay Moshe Maarten Vanbel Ventsislav Kolev Valev Thierry Verbiest David Dressler Yitzhak Mastai

In this paper, we describe for the first time the synthesis of new chiral nanosized metal oxide surfaces based on chiral self-assembled monolayers (SAMs) coated with metal oxide (TiO2) nanolayers. In this new type of nanosize chiral surface, the metal oxide nanolayers enable the protection of the chiral self-assembled monolayers while preserving their enantioselective nature. The chiral nature ...

Journal: :Nature materials 2005
Shu-Hong Yu Helmut Cölfen Klaus Tauer Markus Antonietti

Morphosynthesis strategies inspired by biomineralization processes gives access to a wide range of fascinating and useful crystalline mesostructures. Biomimetic synthesis of inorganic materials with complex shapes can now be used to control the nucleation, tensorial growth, and alignment of inorganic crystals in a way previously not practicable. Double hydrophilic block copolymers (DHBCs) consi...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید