Letters in Organic Chemistry

ISSN: 1570-1786

Letters in Organic Chemistry
Volume 3, Number 10, October 2006

Preparation and Spectroscopic Characterization of 3’-Oxolutein Pp. 723-734

3’-Oxolutein (1) was prepared in highly pure crystalline state and was characterized by spectroscopic methods. The complete assignment of the 13C-NMR spectrum and a thorough interpretation of CD spectrum of this carotenoid is presented for the first time. Spectroscopic data of the newly isolated oxidation product of lutein suggests it has a unique alternative structure (8).

[Back to top]

Study on Host-Guest Complexation of Anions Based on 2,2’-Dihydroxyl-1,1’- Binaphtalene Derivatives Pp. 735-740

Kazuaki Ito, Mio Takahashi, Takuya Hoshino, Makoto Nishiki & Yoshihiro Ohba 2,2'-Dihydroxyl-1,1'-Binaphthalenes (BINOLs) are shown to bind dihydrogen phosphate and acetate selectively over various other anions.

[Back to top]

An Asymmetric Synthesis of the β-Hydroxy Acid Segment of Hapalosin Pp. 741-743

Anubha Sharma, Siddharth Roy, Dibakar Goswami, Angshuman Chattopadhyay & Subrata Chattopadhyay The title compound was synthesized starting from the product obtained by a diastereoselective crotylation of a glyceraldehyde derivative.

[Back to top]

[Back to top]

1,2-Glycerol Carbonate: A Versatile Renewable Synthon Pp. 744-748

Ana-Catarina Simão, Benita Lynikaite-Pukleviciene, Cyril Rousseau, Arnaud Tatibouët, Activated 1,2-glycerol carbonate has been subjected to nucleophilic substitution with oxygen-, nitrogen- and sulfur nucleophiles. Selective reactions with thiol derivatives have been especially investigated for the preparation of mono- and dithiofunctionalized 3-carbon synthons.

[Back to top]

An Approach to Preparation of α -Hydroxyl Cyclobutanones from 1, 2-Bis(trimethylsiloxy) cyclobutene Catalyzed by MgI2 Etherate Pp. 749-752

Xingxian Zhang We describe an efficient and practical preparation of α-hydroxyl cyclobutanones from 1,2-Bis(trimethylsiloxy)cyclobutene (BTCB) with aromatic aldehydes, α,β-unsaturated aldehydes and their parent acetals catalyzed by 1-5 mol% of MgI2 etherate (MgI2•(OEt2)n) in dichloromethane under mild reaction conditions in good yields.

[Back to top]

Pre-Shaped Aromatic Picket Porphyrins Bearing Neutral Oxygen Donors and their Bismuth Complexes: Synthesis and Coordination Studies Pp. 753-758

Lydie Michaudet, Zakaria Halime, Mohammed Lachkar & Bernard Boitrel Bismuth insertion was studied for various porphyrins bearing neutral oxygen donors on aromatic pickets.

[Back to top]

Synthesis of Pyrido[3,2-c]coumarin Derivatives by an Intramolecular Cyclization of 4-Methyl-2-(ortho-methoxyphenyl)nicotinic Acid Using Eaton’s Reagent Pp. 759-763

Yoshinobu Tagawa, Kenji Yamagata & Kunihiro Sumoto The reaction of 4-methyl-2-(methoxyphenyl) nicotinic acid with Eaton’s reagent (P2O5– CH3SO3H) affords pyrido[3,2-c]coumarin derivatives or 1-methyl-4-azafluoren-9-ones depending on the position of the methoxy group on the benzene ring.

[Back to top]

Lipase-Catalyzed Enantioselective Acetylation of Prochiral N-Cbz-2-Alkyl-2-amino-1,3-propanediols and Enantiodivergent Synthesis of α-Benzylserine Pp. 764-767

Shigeki Sano, Michiyasu Nakao, Masanori Takeyasu, Takashi Honjo & Yoshimitsu Nagao Enzymatic acetylation of N-Cbz-2-alkyl-2-amino-1,3-propanediols with lipase afforded N-Cbz-3-acetoxy-2-alkyl-2-amino-1-propanols in up to 98% ee, that offered a facile enantiodivergent synthesis of α-substituted serines.

[Back to top]

BiOClO4•xH2 O and Bi(OTf)2 as Efficient and Environmentally Benign Catalysts for Synthesis of Bis(indolyl)methanes in Solution and Under Ultrasound Irradiation Pp. 768-772

Iraj Mohammadpoor-Baltork, Hamid Reza Memarian, Ahmad Reza Khosropour & Kobra Nikoofar An efficient and selective method for the synthesis of bis(indolyl)methanes by reactions of indoles with aldehydes and ketones in the presence of catalytic amounts of BiOClO4•xH2 O and Bi(OTf)3 in solution and under ultrasound irradiation is reported.

[Back to top]

An Efficient and Selective End-Modification of High-Molecular Weight Poly(Ethylene Glycol)s Pp. 773-779

Pietro Campaner, Gian Maria Bonora & Sara Drioli Poly(ethylene glycol)s can be efficiently and selectively end-modified. Terminal amino functions, orthogonally protected, have been introduced and mixed conjugated drugs can be obtained.

[Back to top]

Facile Synthesis of C3-Symmetric Tripodal β-Hydroxy Amide Ligands and Their Ti (IV) Complex-Catalyzed Asymmetric Addition of Diethylzinc to Aldehydes Pp. 780-786

Tao Fang, Jiaxi Xu & Da-Ming Du Chiral C3-symmetric tripodal tris(β-hydroxy amide) and corresponding tris(amino alcohol) ligands have been synthesized conveniently. The asymmetric diethylzinc addition to various aldehydes catalyzed by chiral C3-symmetric tripodal tris(β-hydroxy amide) ligand-Ti (IV) complexes were investigated. Modest enantioselectivities were obtained.

[Back to top]

[Back to top]

Michael Addition of Thiols to α-Enones: Is Any Catalyst Necessary? Pp. 794-797

Michael addition of thiols to α-enones without any catalyst was accomplished in ionic liquids, water, conventional organic solvents, under solvent-free conditions.

[Back to top]