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A hydrogen/deuterium isotopic substitution neutron diffraction technique that was used to measure the structural correlation functions of liquid tetrahydrofuran at room temperature is presented. Analysis to the level of the orientational correlation functions shows that the liquid displays a preference for T-like configurations between the tetrahydrofuran molecules, a local structure that results in voidlike regions of approximately 1.25 A(degree) radius within the bulk liquid.

Cyclic voltammetric studies of Zn-Mn- and Al-reduced Cp2TiCl2 solutions in tetrahydrofuran (THF) were conducted. Results show that (CP2 TiCl)2 are the species responsible for product formation under catalytic conditions.

A macrodiolide antibiotic pamamycin-607 was synthesized by joining two hydroxy acid components. Three cis-2, 5-disubstituted tetrahydrofuran rings were stereoselectively introduced via radical cyclization reactions of beta-alkoxyvinyl ketone intermediates and a beta-alkoxymethacrylate substrate.

The fully unrestrained molecular dynamics simulations starting from several members of the family of structures are reported, and these simulations support the existence of an AT base pair. These simulations strengthen the hypothesized presence of the A:T base pair and provides a possible explanation for missing experimental data.

The spectroscopic information of ternary aniline clusters, which included water, was obtained by infrared depletion spectroscopy. The infrared spectrum of the neutral cluster showed four absorption bands at 3715 cm(super -1) (free OH), 3491 cm(super -1) (free NH), 3403 cm(super -1) (bonded OH) , and 3376 cm(super -1) (bonded NH).

Bicyclic C-fused chlorinated tetrahydrofuro[3,2-c]azetidin-2-ones are prepared by a general route involving Staudinger reaction of allylic/propargylic imidates with dichloroketene followed by highly diastereoselective CuCl/PMDETA-catalyzed 5-exo-trig/dig chlorine atom transfer radical cyclization. Synthetic application of the side chain chlorine atom of the products is shown by its substitution in one of the products with azide followed by azide-alkyne click reaction with phenylacetylene to obtain a 1,2,3-triazolyltetrahydrofuro[3,2-c]azetidin-2-one.

The NMR spectroscopic analysis has shown that it is possible to perform highly enantioselective asymmetric deprotonation reaction by using i-PrLi or s-BuLi/(+)-sparteine surrogate in THF. The studies have shown that these are the first examples of highly enantioselective asymmetric deprotonation reactions by using organolithium/diamine complexes in THF.

A Lewis acid-catalyzed cyclization of homochiral (S)-vinylcyclopropane diester and N-tosylindole-2-carboxaldehyde to construct the tetrahydrofuran ring was utilized to achieve the asymmetric total synthesis of (+)-isatisine A. The key steps in the total synthesis involved an indole oxidation and electrophilic aromatic substitution sequence to construct isatisine A acetonide, which was then carried forward to the antipode of the natural product.

A research program is developed for achieving synthesis of tetrahydrofurans from cyclopropanes and C[double bond]O [pi] bonds. Asymmetric syntheses of (+)-polyanthellin A and (+)-virgatusin are achieved, which have depended upon cyclopropane/aldehyde annulation for construction of the core tetrahydrofurans.

An asymmetric total synthesis of trilobacin, an annonaceous acetogenin with potent anticancer activities is presented. The constructed erythro-bis(2,2')-tetrahydrofuran core featured a novel organoselenium-mediated oxonium ion formation/Si[O.sub.2]-promoted fragmentation of [alpha],[alpha]'-cis-oxocene.

A series of 4-arylsulfonylimino-4,5-dihydrofurans are prepared by using copper-catalyzed three-component reaction between sulfonyl azides, phenylacetylene and [beta]-ketoesters in tetrahydrofuran (THF) in the presence of triethylamine (TEA). A plausible mechanism is proposed for the process.

A new ambient-temperature, catalyst-free reaction between ammonia borane and tetrahydrofuran borane has produced aminodiborane by the formation of a dihydrogen bond and subsequent molecular hydrogen elimination. Aminodiborane is used for preparing an inorganic butane analogue, N[H.sub.3]B[H.sub.2]N[H.sub.2]B[H.sub.3], and its single-crystal structure has exhibited a gauche rather than an anti form conformation.

The kinetics and mechanism of rearrangement of S-(2-oxotetrahydrofuran-3-yl)-N-(4-methoxyphenyl)isothiuronium bromide into 5-(2-hydroxyethyl)-2-[(4-methoxyphenyl)imino]-1,3-thiazolidin-4-one are analyzed under pseudo-first-order reaction conditions in aqueous buffer solutions and in diluted HCl. The coexistence of all three kinetically detectable intermediates is very rare and is because of enhanced stability of these intermediates necessitating participation of an acid for progression to products.

Carbanions of aryl 3-chloropropylsulfoxides have reacted with nonenolizable aldehydes to provide 2,3-disubstituted tetrahydrofurans. The diastereoselectivity is attributed to the cyclic transition state of the aldol addition and has increased when the aromatic ring of the sulfoxide contains electron-withdrawing subsituents, whereas that of the aldehyde has electron-donating groups.

An unprecedented diene-assisted transition-metal-catalyzed activation of allylic C-H bonds and their subsequent insertion into the alkene moieties of conjugated dienes is described. The C-H activation/alkene insertion has provided an efficient way to prepare polysubstituted tetrahydropyrroles, tetrahydrofurans and cyclopentanes with quaternary carbon centers and the studies have shown that allylic C-H activation and alkene insertion are reversible steps, whereas the reductive elimination step is irreversible.

A total synthesis of the Aspidosperma alkaloids (+)-fendleridine and (+)-1-acetylaspidoalbidine is described, which has provided access to both enantiomers of the natural products and has established their absolute configuration. The final tetrahydrofuran bridge is installed in one step, which has enlisted an intramolecular alcohol addition to an iminium ion generated by nitrogen-assisted opening of the cycloadduct oxido bridge, with a modification that has permitted release of useful functionality at the cleavage termini.

A new and efficient method was developed for the synthesis of substituted quinolines via intramolecular electrophilic cyclization of 1-azido-2-(2-propynyl)benzene. The cyclization reaction was performed in the of electrophilic reagents ([I.sub.2], [Br.sub.2], ICl, NBS, NIS, and HNT[f.sub.2]) in [CH.sub.3]N[O.sub.2] at room temperature or in the presence of catalytic amounts of Au[Cl.sub.3]/AgNT[f.sub.2] in THF at 100 degree [Celsius] to afford the corresponding quinolines.

Computational studies on ion-pair separation (IPS) of THF-solvated fluorenyl, diphenylmethyl, and trityl lithium is are presented. The detailed study results provide insight into energy equilibrium geometries, enthalpies, and exothermicity of IPS.

The synthesis and characterization of the various tuning redox-active amido-tetrathiafulvalene derivatives present in the paramagnetic coordination complexes are discussed. The analysis also explains their photophysical properties and the transition mechanisms.

Several studies are conducted to explain the synthesis and the magnetic properties of the various di- and trinuclear uranium(IV) ethynylbenzene complexes. The structure and the ferro- and antiferromagnetic coupling of these compounds are also discussed.

Pyridine nitriles and esters are metalated at the position next to the directing group by using [(TMP).sub.3]CdLi in tetrahydrofuran. Ethyl iodopyridinecarboxylates are involved in a one-pot palladium-catalyzed cross-coupling reaction/cyclization by using 2-aminoyridine to produce new dipyridopyrimidinones.

A rapid repetitive solution-phase synthesis of peptides is described, where the procedure has involved coupling of amino acids and peptide acids to slight excesses of pentafluorophenyl active esters in a THF/water solvent mixture. The efficiency of the method is shown by the rapid synthesis of short hydrophobic and hydrophilic peptides, the antimalarial cycloheptapeptide mahafacyclin B, and a protected form of the hydrophilic pentapeptide GRGDS.

The synthesis by Suzuki cross-coupling methodology of oligo(arylene) molecular wires with protected thiolates at both termini and a central electron-acceptor unit (3,5-dinitrofluorenone) or an electron-donor unit [9-(1,3-dithiol-2-ylidene)fluorene] in the backbone is described. The studies have shown that thiolated molecules that possess strongly electron-withdrawing core units containing nitro groups are not suitable for controlled assembly in junctions.

A simple, efficient, and environmentally benign method for the synthesis of 3-alkoxymethylcoumarin is described. The process involved reaction of 3-cyanochromene with an alkoxide and arylamine in t etrahydrofuran (THF) to obtain (Z)-2-phenylimino-3-alkoxymethylchromene as a novel novel intermediate via an isomerization of the double bond.

The bisstannylation has produced the corresponding bisstannylated cis-adducts by treating various fluorinated internal alkynes with hexabutylditin under the affect of Pd[(t-BuNC).sub.2][Cl.sub.2] in THF at room temperature. These adducts are subjected to the Stille cross-coupling reaction to give the corresponding tetrasubstituted fluorine-containing alkenes with defined stereochemistry.

The selective N-methylation of BOC-protected valine with MeI and NaH in THF is attributed to the protection of the carboxylate by chelation to [Na.sup.+]. An alternative mechanism, involving the formation of the carbene intermediate generated from MeI and its insertion into the N-H bond, is ruled out by isotopic labeling.

The cycloadditions of vinylidenecyclopropanes with aldehydes are described for the preparation of tetrahydrofurans. The cycloadditions of vinylidenecyclopropanes with aldehydes and the transformations of the cycloadducts have provided an efficient protocol for constructing various medium- and large-size ring-fused tetrahydrofuran, furan, and benzo[c]fluorene derivatives.

Proazaphosphosphatrane is an efficient catalyst for Mukaiyama aldol reactions of aldehydes with trimethylsilyl enolates in THF solvent. Heterocyclic aldehydes, such as pyridine-2-carboxaldehyde, benzofuran-2-carboxaldehyde, benzothiophene-2-carboxaldehyde, and 1-methyl-2-imizadolecarboxaldehyde, have produced Mukaiyama products in good yields.

Hydrogen hydrates with tetrahydrofuran (THF) as a promoter molecule are explored to probe critical unresolved observations regarding cage occupancy and storage capacity. The results showed that the hydrogen storage capacity could be increased to ~3.4 wt % in the THF+[H.sub.2] hydrate system by manipulating the promoter THF content.