Asymmetric Synthesis of Pyrido[1,2-c]pyrimidinones

“Asymmetric Electrophilic α-Amidoalkylation” reactions with a chiral alkylaminocarbonyl unit as chiral auxiliary are used for the stereoselective synthesis of 2-substituted piperidine derivatives. Intramolecular condensation of the nitrogen of the aminocarbonyl group with the keto function present in the newly introduced side chain of the amidoalkylation products results in the formation of hexahydropyrido[1,2-c]pyrimidinones. After reduction and removal of the N-alkyl moiety of the chiral auxiliary the target compounds, enantiopure octahydro-1H-pyrido[1,2-c]pyrimidin-1-ones, are obtained.

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Asymmetric Synthesis of Tetrahydroisoquinoline Alkaloids Using Ellman's Chiral Auxiliary

Natural Product Communications ◽

10.1177/1934578x1701201019 ◽

2017 ◽

Vol 12 (10) ◽

pp. 1934578X1701201

Author(s):

Y. Vikram Reddy ◽

Dhanraj O. Biradar ◽

B. Jagan Mohan Reddy ◽

Aravinda Rathod ◽

M. Himabindu ◽

...

Keyword(s):

Natural Products ◽

Asymmetric Synthesis ◽

Stereoselective Synthesis ◽

Chiral Auxiliary ◽

First Report

Chiral t-butylsulfinamide has been successfully employed for the stereoselective synthesis of 1-benzyl tetrahydroisoquinoline alkaloids. This is the first report on the synthesis of chiral 1-benzyltetrahydroisoquinoline natural products using tert-butylsulfinamide through a haloamide cyclization.

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Indium Bromide-catalyzed Unprecedented Hydrogenolysis: A Novel One-Pot Synthesis of Per-O-Acetylated β-carboxymethyl O and S-glycosides

Current Organic Chemistry ◽

10.2174/1385272824999200407093625 ◽

2020 ◽

Vol 24 (8) ◽

pp. 900-908

Author(s):

Ram Naresh Yadav ◽

Amrendra K Singh ◽

Bimal Banik

Keyword(s):

Asymmetric Synthesis ◽

Chiral Auxiliary ◽

Bioactive Molecules ◽

One Pot ◽

Enantiomerically Pure ◽

Stereoselective Glycosylation ◽

One Pot Synthesis ◽

Wide Range

Numerous O (oxa)- and S (thia)-glycosyl esters and their analogous glycosyl acids have been accomplished through stereoselective glycosylation of various peracetylated bromo sugar with benzyl glycolate using InBr3 as a glycosyl promotor followed by in situ hydrogenolysis of resulting glycosyl ester. A tandem glycosylating and hydrogenolytic activity of InBr3 has been successfully investigated in a one-pot procedure. The resulting synthetically valuable and virtually unexplored class of β-CMGL (glycosyl acids) could serve as an excellent potential chiral auxiliary in the asymmetric synthesis of a wide range of enantiomerically pure medicinally prevalent β-lactams and other bioactive molecules of diverse medicinal interest.

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Investigation of the Anti-Methicillin-Resistant Staphylococcus aureus Activity of (+)-Tanikolide- and (+)-Malyngolide-Based Analogues Prepared by Asymmetric Synthesis

International Journal of Molecular Sciences ◽

10.3390/ijms22126400 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6400

Author(s):

Joseph Breheny ◽

Cian Kingston ◽

Robert Doran ◽

Joao Anes ◽

Marta Martins ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Asymmetric Synthesis ◽

Methicillin Resistant Staphylococcus Aureus ◽

Antimicrobial Properties ◽

Side Chain ◽

Alkyl Side Chain ◽

Methicillin Resistant ◽

Antibacterial And Antifungal

Herein, we report antibacterial and antifungal evaluation of a series of previously prepared (+)-tanikolide analogues. One analogue, (4S,6S)-4-methyltanikolide, displayed promising anti-methicillin-resistant Staphylococcus aureus activity with a MIC of 12.5 µg/mL. Based on the antimicrobial properties of the structurally related (−)-malyngolide, two further analogues (4S,6S)-4-methylmalyngolide and (4R,6S)-4-methylmalyngolide bearing a shortened n-nonyl alkyl side chain were prepared in the present study using a ZrCl4-catalysed deprotection/cyclisation as the key step in their asymmetric synthesis. When these were tested for activity against anti-methicillin-resistant Staphylococcus aureus, the MIC increased to 50 µg/mL.

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