Month: July 2012

Efficient levoglucosenone production

Levoglucosenone Levoglucosenone is a highly dehydrated sugar that has been used in the preparation of chiral synthons such as (–)-y-multistriatin and (+)-Prelog—Djerassi lactonic acid. Negative-form is a pyrolysis product of cellulose and cellulose-containing materials including pulp and paper waste products. Known as a pyrolytic product of cellulose, which is very useful as a chiral source… Continue reading Efficient levoglucosenone production

Isolation of Optically Pure (S)-(+)-Ibuprofen

Isolation of Optically Pure (S)-(+)-Ibuprofen In this laboratory exercise we will isolate (S)-(+)-Ibuprofen from a racemic mixture of both enantiomers of this compound. This will be accomplished by treating the racemic mixture of Ibuprofen with (S)-(-)-alpha-Phenethylamine, whose molecules are themselves chiral, to form (S,S) and (R,S) Ibuprofen/Phenethylamine diastereomeric salts. Because the (S,S) salt is much… Continue reading Isolation of Optically Pure (S)-(+)-Ibuprofen

Resolution-Racemization-Recycle.

In one of its steps the racemic alcohol 1 is dissolved in a mixture of toluene and methanol to which solution is added optically active (S)-mandelic acid 3. The alcohol (S)-enantiomer forms an insoluble diastereomeric salt with the mandelic acid and can be filtered from the solution. Simple deprotonation with sodium hydroxide liberates free (S)-alcohol. In the meanwhile the (R)-alcohol remains in solution unaffected and is recycled back… Continue reading Resolution-Racemization-Recycle.

Synthesis of Chiral Pyridylphenols for the Enantioselective Addition of Diethylzinc to Aldehydes

Synthesis of Chiral Pyridylphenols for the Enantioselective Addition of Diethylzinc to Aldehydes 很高兴看到来自中国的精彩文章 http://onlinelibrary.wiley.com/doi/10.1002/jccs.201100474/abstract DOI: 10.1002/jccs.201100474 Chiral 8-substituted 2-(8,10,10-trimethyl-6-aza-tricyclo[7.1.1.02,7]undeca-2(7),3,5-trien-5-yl)-phenols were prepared from a high enantiopurity (>97% ee) of (1R)-(+)-alpha-pinene, and assessed in the enantioselective addition of diethylzinc to substituted benzaldehydes, giving the (S)-alcohols with enantiomeric excess ranging from 33% to 89%. Interestingly, in all cases,… Continue reading Synthesis of Chiral Pyridylphenols for the Enantioselective Addition of Diethylzinc to Aldehydes

IMATINIB…..

Medicine for Blood Cancer ‘Imitinef Mercilet’ is a medicine which cures blood cancer. Its available free of cost at “Adyar Cancer Institute in Chennai”. Create Awareness. It might help someone.Cancer   Institute in Adyar, Chennai ‘Imitinef Mercilet’ is apparently an alternative spelling of the drug Imatinib mesylate which is used in the treatment of some… Continue reading IMATINIB…..

Pd-catalyzed coupling reactions of 1,1-dibromo-1-alkenes with various arylboronic acids in Aqueous Solution

Effective Palladium-Catalyzed Synthesis of Triarylethene-Based Molecules in Aqueous Solution Yan Zhu, et al DOI: 10.1002/ejoc.201200577 http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201200577/abstract  Highly effective and selective Pd-catalyzed coupling reactions of 1,1-dibromo-1-alkenes with various arylboronic acids have been performed in aqueous solution under mild conditions. The method is simple, economic, and practical for the synthesis of triarylethene-based compounds.     General procedure for… Continue reading Pd-catalyzed coupling reactions of 1,1-dibromo-1-alkenes with various arylboronic acids in Aqueous Solution

Aldol condensation: A simple teaching model for organic laboratory

Aldol condensation: A simple teaching model for organic laboratory link http://pubs.acs.org/doi/abs/10.1021/ed055p540 To synthesize trans-dibenzalacetone from acetone and benzaldehyde using NaOH as the catalytic base in a 1:1 water/ethanol solvent Procedure Prepare a 0.5M NaOH (20 mmol) solution in 40 mL of distilled water and prepare a 1M solution of benzaldehyde (40 mmol) in 40 mL… Continue reading Aldol condensation: A simple teaching model for organic laboratory

SYNTHESIS OF UGI ADDUCT

  To synthesize a Ugi aduct from Benzaldehyde, Furfuryl amine, Benzylisocyanide and BOC-GLY-OH in methanol using Ugi 4Component Reaction. BOC-GLY-OH,  STR IS Procedure A solution of Benzaldehyde (212 uL, 2.09 mmol) and Furfuryl amine (FFA) (235uL, 2.66 mmol )was prepared in methanol-d4 in a 4mL volumetric flask to form an imine overnight. The next day a solution of BOC-GLY-OH(350 mg, 1.99 mmol), andBenzylisocyanide (240uL,… Continue reading SYNTHESIS OF UGI ADDUCT