16408-83-6

Basic information

• Product Name: Tetrahydro-2-(2,2,2-trifluoroethoxy)-2H-pyran
• Synonyms: Tetrahydro-2-(2,2,2-trifluoroethoxy)-2H-pyran
• CAS NO: 16408-83-6
• Molecular Formula: C7H11F3O2
• Molecular Weight: 184.16
• Mol File: 16408-83-6.mol
• Article Data: 5

Chemical Properties

• Appearance: /
• CAS DataBase Reference: Tetrahydro-2-(2,2,2-trifluoroethoxy)-2H-pyran(CAS DataBase Reference)
• NIST Chemistry Reference: Tetrahydro-2-(2,2,2-trifluoroethoxy)-2H-pyran(16408-83-6)
• EPA Substance Registry System: Tetrahydro-2-(2,2,2-trifluoroethoxy)-2H-pyran(16408-83-6)

Safety Data

• Hazardous Substances Data: 16408-83-6(Hazardous Substances Data)

Upstream product

• 110-87-2 3,4-dihydro-2H-pyran 
• 75-89-8 2,2,2-trifluoroethanol 

Relevant articles and documents

Cyclopropenium Enhanced Thiourea Catalysis

An integral part of modern organocatalysis is the development and application of thiourea catalysts. Here, as part of our program aimed at developing cyclopropenium catalysts, the synthesis of a thiourea-cyclopropenium organocatalyst with both cationic hydrogen-bond donor and electrostatic character is reported. The utility of the this thiourea organocatalyst is showcased in pyranylation reactions employing phenols, primary, secondary, and tertiary alcohols under operationally simple and mild reaction conditions for a broad substrate scope. The addition of benzoic acid as a co-catalyst facilitating cooperative Br?nsted acid catalysis was found to be valuable for reactions involving phenols and higher substituted alcohols. Mechanistic investigations, including kinetic and 1H NMR binding studies in conjunction with density function theory calculations, are described that collectively support a Br?nsted acid mode of catalysis.

EXPERIMENTAL STUDIES OF THE ANOMERIC EFFECT. PART IV. CONFORMATIONAL EQUILIBRIA DUE TO RING INVERSION IN TETRAHYDROPYRANS SUBSTITUTED AT POSITION 2 BY THE GROUPS ETHOXY, 2'-FLUOROETHOXY, 2',2'-DIFLUOROETHOXY, AND 2',2',2'-TRIFLUOROETHOXY

Equilibrium constants (K) for ring inversion equilibria in 2-(RO)-tetrahydropyrans (R = Et, CH2CH2F, CH2CHF2, CH2CF3) have been determined from 13C nmr spectra recorded at 145-160 K in CD2Cl2 and CFCl3/CDCl3 (85/15 by volume).Additional values of K were obtained at 250-270 K from the acid-catalysed equilibration of cis- and trans-2-(RO)-4-methyl-tetrahydropyran (R as above).Plots of lnK against T-1 gave values for ΔH0a->e of -0.26, -0.12, -0.05 and 0.13 kcal mol-1 for R = Et, CH2CH2F, CH2CHF2 and CH2CF3, respectively, in CD2Cl2.The corresponding values of ΔH0a->e for CFCl3/CDCl3 as solvent were -0.58, -0.15, -0.07 and 0.21 kcal mol-1, respectively.The derived ΔS0a->e values were -2.33, -2.22, -2.25 and -2.24 cal K-1mol-1, respectively, in CD2Cl2 and -4.65, -3.37, -3.30 and -3.03 cal K-1mol-1, respectively, in CFCl3/CDCl3. The trends in ΔH0 values are attributed to modifications of anti-periplanar n->o* stabilisation (itself partly responsible for endo- and exo-anomeric effects) which occur as the number of electronegative fluorine substituents increases.For all substituents, axial conformations are the most abundant in the temperature range 120 K to infinite.However, this finding is a consequence of the higher entropy of axial conformations; in at least two cases (R = Et and CH2CH2F) it is the equatorial conformation which has the lower enthalpy.The results confirm the importance of studying conformational equilibria over a wide range of temperature.