Related Experiment Video
Updated: Jun 1, 2026
09:14
Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine
Published on: February 16, 2018
A functionalized enol lactone containing a protected α-amino acid
Summary
The crystal structure of a novel pyrano[3,2-c]chromene derivative was determined using X-ray diffraction. This study provides insights into its molecular arrangement and electronic properties via computational analysis.
Area of Science:
- Crystallography
- Organic Chemistry
- Computational Chemistry
Background:
- Pyrano[3,2-c]chromene derivatives are known for diverse biological activities.
- Understanding the precise molecular structure is crucial for structure-activity relationship studies.
Purpose of the Study:
- To determine the crystal structure of N-(3,9-dimethyl-4-phenyl-2,5-dioxo-3,4-dihydro-2H,5H-pyrano[3,2-c]chromen-3-yl)-N-methylbenzamide methanol monosolvate.
- To investigate the structural parameters and compare them with theoretical calculations.
Main Methods:
- Single-crystal X-ray diffraction at room temperature.
- Ab initio computational calculations.
Main Results:
- The crystal structure of the title compound (C(28)H(23)NO(5)·CH(3)OH) was successfully elucidated.
- Key structural parameters, including bond lengths, bond angles, and intermolecular interactions, were obtained.
- Comparison between experimental and calculated structural data was performed.
Conclusions:
- The study provides definitive crystallographic data for the novel pyrano[3,2-c]chromene derivative.
- The integration of experimental and computational methods offers a comprehensive understanding of the molecule's structure.
Related Concept Videos
01:18Reactivity of Enols
Enols are a class of compounds where a hydroxyl group is attached to a carbon–carbon double bond, which implies that it is a vinyl alcohol. A carbonyl compound with an α hydrogen undergoes keto–enol tautomerism and remains in equilibrium with its tautomer, the enol form. Usually, the keto tautomer is present in a higher concentration than the enol tautomer due to the higher bond energy of C=O compared to C=C. Moreover, the direction of the keto–enol equilibrium is governed by factors like...
01:10α-Alkylation of Ketones via Enolate Ions
Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the strong interaction...
01:07Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an alkylated β-keto acid.
01:14Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.
01:23Protecting Groups for Aldehydes and Ketones: Introduction
Protecting groups are compounds that can bind to a specific functional group in the presence of other functional groups to protect them from undesired chemical reactions. These compounds can selectively bind to particular functional groups and advance chemoselective reactions in polyfunctional systems (Figure 1). After the functional group has served its purpose, it is removed by reacting it with specific compounds.
01:33Regioselective Formation of Enolates
As depicted in the figure below, the unsymmetrical ketones can form two possible enolates: less substituted or more substituted enolates. Usually, the thermodynamic enolates are formed from the more substituted α-carbon atom, while the kinetic enolates are formed faster by deprotonation from the less substituted position. The thermodynamic enolates have lower energy, so they are more stable. But the energy required to form kinetic enolates is less.