ChemInform Abstract: An Efficient, Selective Hydrolysis of Terminal Isopropylidene Acetal Protection by Zn(NO3)2×6H2O in Acetonitrile.

Vijayasaradhi, Sivalenka; Singh, Jaimala; Aidhen, Indrapal Singh

doi:10.1002/chin.200017204

Cited by 6 publications

(5 citation statements)

References 4 publications

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“…Having established the means for the rapid detection of 1,2‐acyl migration and a feasible and reliable method for measuring the ee values of 1(or 3)‐acyl‐ sn ‐glycerols, we went on to examine several sets of promising mild conditions for cleaving acetonides, including CF 3 CO 2 H (50 % aq. )/CH 2 Cl 2 ,10 H 3 BO 3 /HO(CH 2 ) 2 OMe/reflux,2c,2f,2k Zn(NO 3 ) 2 /MeCN,11 and HOAc/H 2 O (4:1) 2a. The results are summarized in Table 1.…”

Section: Resultsmentioning

confidence: 91%

Optically Active Monoacylglycerols: Synthesis and Assessment of Purity

et al. 2013

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Despite their simple structures, synthesis of 1(or 3)‐acyl‐sn‐glycerols remains a challenge that cannot be ignored because of facile acyl migrations, which not only complicate the synthesis but also make direct GC or HPLC analysis unfeasible. Assessment of the optical purity of monoacylglycerols has, to date, relied almost exclusively on specific rotation data, which are small in value and thus insensitive to impurities. Now, a simple means to “magnify” the small specific rotations has been found, along with practical methods for the measurement of both 1,2‐ and 1,3‐acyl migrations, which offer a convenient and straightforward alternative to Mori's NMR analysis of Mosher esters. With the aid of these methods, a range of conditions for deacetonide removal were examined en route to the synthesis of two natural monoacylglycerols. Refined hydrolysis conditions, along with useful knowledge about the solubility and reactivity of substrates with an ultra long alkyl chain are also presented.

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Section: Resultsmentioning

confidence: 91%

Optically Active Monoacylglycerols: Synthesis and Assessment of Purity

et al. 2013

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“…Olefin 24-D was transformed into enyne 34 , the substrate for radical cyclization (Scheme ). The terminal acetonide of 24-D was chemoselectively hydrolyzed using Zn(NO 3 ) 2 ·6H 2 O in MeCN . Oxidative cleavage of incoming diol 27 followed by borohydride reduction gave alcohol 28 , which was converted into iodide 30 via mesylate 29 .…”

Section: Resultsmentioning

confidence: 99%

Stereoselective Synthesis of the Tricyclic Core of (−)-Callophycoic Acid A

et al. 2020

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Two stereocontrolled routes to the tricyclic core of (−)-callophycoic acid A are described. Our synthetic strategy relied on stereoselective allylboration using a new allylboronate reagent to construct the all-carbon quaternary stereocenter in the core, followed by efficient radical cyclization or palladium-catalyzed reductive cyclization to form its multisubstituted cyclohexane ring. The tetrahydrooxepin ring was constructed by intramolecular etheration. This study provides the first method for the stereoselective synthesis of the characteristic tricyclic skeleton of callophycoic acids.

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“…The nature of protections in the arabino ‐configured iodo derivative 33 is crucial for cyclization to pyranosides. Although, the arabino ‐configured iodide 38 with two di‐isopropylidene ketals, readily afforded the corresponding phenyl ketones 39 and also allowed for selective removal of the terminal isopropylidene protection with Zn (NO 3 ) 2 [41a] for the formation of phenyl‐glycosyl ketone 40 , and no cyclization to pyranoside product 41 was seen (Scheme 6). [42] The rigid conformational locking across the internal dioxolane ring is presumably responsible, for cyclization termini not reaching each other.…”

Section: Research Work At Iit‐madrasmentioning

confidence: 99%

Natural Products & Bioactivity Inspired Synthetic Pursuits Interfacing with Carbohydrates: Ongoing Journey with C‐Glycosides

Aidhen

Thoti

2021

The Chemical Record

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Natural products, remains the most important source for the discovery of new drugs for the treatment of human diseases. This has inspired the synthetic community to design and develop mimics of natural products either to answer important questions in biology or to explore their therapeutic potentials. Glycosides present themselves abundantly in nature, right from the cell surface receptors to natural products of any origin. The O-Glycosides are hydrolytically less stable compared to C-glycosides and this feature has presented a great opportunity for drug discovery. The discovery of Dapagliflozin, an SGLT inhibitor and C-glucoside, for the treatment of diabetes is one such example. Aryl acyl-anion chemistry has been explored for the synthesis of 2-deoxy-C-aryl furanoside/pyranoside/septanosides. Besides success, the studies have provided valuable insight into the natural propensities of the architectural framework for the cascade to furan derivatives. The aryl acyl-anion chemistry has also enabled the synthesis of biologically active diaryl heptanoids. Inspired from sucesss of Dapagliflozin, new analogues have been synthesized with pyridine and isocoumarin heterocycle as the proximal ring. C-glucosides of isoliquiritigenin have been synthesized for the first time and evaluated as an efficient aldose reductase inhibitor. The synthesis and evaluation of acyl-C-β-D-glucosides and benzyl-C-β-Dglucoside as glucose-uptake promoters has revealed promise in small molecules. The concept of building blocks has been used to obtain natural oxylipins, D-xylo and L-xylo-configured alkane tetrols and novel lipophilic ketones with erythro/threo configured trihydroxy polar head-group as possible anti-mycobacterial agents.

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ChemInform Abstract: An Efficient, Selective Hydrolysis of Terminal Isopropylidene Acetal Protection by Zn(NO₃)₂×6H₂O in Acetonitrile.

Cited by 6 publications

References 4 publications

Optically Active Monoacylglycerols: Synthesis and Assessment of Purity

Optically Active Monoacylglycerols: Synthesis and Assessment of Purity

Stereoselective Synthesis of the Tricyclic Core of (−)-Callophycoic Acid A

Natural Products & Bioactivity Inspired Synthetic Pursuits Interfacing with Carbohydrates: Ongoing Journey with C‐Glycosides

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