Synthesis Of Oxa Research Articles

Triple Bond Species in the Synthesis of Oxa(thia)diazoles and Triazoles (A Review)

Triple Bond Species in the Synthesis of Oxa(thia)diazoles and Triazoles (A Review)

Studies Directed towards the Synthesis of the Acridone Family of Natural Products: Total Synthesis of Acronycines and Atalaphyllidines.

A modular and flexible three-step synthetic strategy has been developed for the synthesis of acridone natural products of biological significance. The tetracyclic core of acridone derivatives has been achieved efficiently in high yield from commercially available anthranilic acid and phenol derivatives via condensation reaction, followed by regioselective annulation. Acridone alkaloids acronycine and noracronycine are synthesized in improved overall yields in fewer steps than the previously reported approaches. The method has further been used for the synthesis of atalaphyllidine and 5-hydroxynoracronycine in excellent yields for the first time. Moreover, the synthetic utility of the present strategy has been showcased by the synthesis of oxa and thia analogues of acronycine alkaloid.

Heterocyclization of Cyanoacetamide Derivatives: Synthesis and Biological Activity of Novel Azoles and Azines

The intermolecular cyclization of N-benzyl-2-cyanoacetamide with carbon disulfide followed by intramolecular cyclization gave thioxothiazinone 3. This compound was used to synthesize a series of novel fused furopyrrole, pyridine, pyrimidine and other azine and azole derivatives. The Michael-type reaction of compound 3 with maleic anhydride followed by pyrrole and furan cyclizations and aromatization yielded polycyclic compound 7. The [3+3]-cycloaddition of benzylidene malononitrile and its derivative to compound 3 gave pyridothiazines 10–12. The ring opening in compound 3 under the action of urea or thiourea followed by pyrimidine cyclization and subsequent air oxidation resulted in the synthesis of oxa- and thiadiazolopyrimidinones 15 and 16, respectively. The reaction of compound 3 with H2O2 in a basic medium provided pyrimidine derivative 17. The oxidation of compound 3 with Br2 in an acid medium led to bromo derivative 19. The synthesized novel compounds were characterized by elemental analysis and IR and 1H and 13C NMR spectroscopy and tested antibacterial and anticancer activities.

ChemInform Abstract: Synthesis of Oxa‐, Aza‐ and Thia‐Bowls and Cages

AbstractReview: 147 refs.

Regioselective Synthesis of Oxa- and Thiadiazoles from Thiosemicarbazides

Regioselective Synthesis of Oxa- and Thiadiazoles from Thiosemicarbazides

Synthesis of Oxa-, Aza- and Thia-Bowls and Cages

Synthesis of strained organic molecules has been a topic of interest amongst synthetic and theoretical chemists over the past several years. 1 – 7 Whereas majority of the early efforts in this area...

Novel synthesis of oxa[9]helicenes by Lawesson’s reagent-mediated cyclization of helical quinone derivatives

New oxa[9]helicenes which possess one furan ring have been readily prepared by reactive helical quinone with Lawesson’s reagent or phosphorus pentasulfide in good yields. The versatility of this protocol has been demonstrated with various substituted helical quinones.

ChemInform Abstract: Medium-Membered Ring Ketone Synthesis. Synthesis of Oxa- and Azacyclooctanone Derivatives.

ChemInform Abstract: Medium-Membered Ring Ketone Synthesis. Synthesis of Oxa- and Azacyclooctanone Derivatives.

ChemInform Abstract: Radical Cyclizations: Synthesis of Oxa- and Azaheterocyclic Compounds

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Facile Synthesis of Oxa- and Azacyclic Dienes via Cycloalkenation of Alkynyltungsten Compounds. Stereoselective Construction of Tricyclic Furan and Pyran Derivatives via Intramolecular Diels-Alder Reaction.

A convenient and short synthesis of functionalized oxacyclic and azacyclic dienes is developed on the basis of organotungsten chemistry. Alkynyltungsten compounds bearing a tethered alcohol and ami...

ChemInform Abstract: Synthesis of Oxa‐ and Azapalladacycles from Organostannanes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of Oxa‐ and Azapalladacycles from Organostannanes

An intramolecular Pd–C coupling reaction yields the oxapalladacycle 1. This is the first time that the transmetalation intermediate in the Stille coupling reaction has been isolated. Complexes of type 1 react readily with alkyl, allyl, benzyl, and acyl halides to form aryl-carbon bonds. This reaction can be extended to the preparation of substituted derivatives of 1 and the aza analogue 2.

Medium-Membered Ring Ketone Synthesis. Synthesis of Oxa- and Aza-crclooctanone Derivatives.

As a model study on the synthesis of natural products possessing an eight-membered cyclic ether or amine framework such as laurencin (1) and FR900482 (6), two kinds of 2-benzyl oxacyclooctanones (7 and 8) and 2-methyl azacyclooctanones (9 and 10) were synthesized from the corresponding twelve-membered lactam sulfoxides (49-52) by applying our general method for medium-ring ketone synthesis. The corresponding lactam sulfides were readily prepared from the linear ω-tosyl carboxylic acids containing on oxygen atom (11 and 12) or methylcarbamate group (13 and 14) by condensation with 2-cyanoethyl 2-N-methylaminophenyl sulfide followed by alkylation.

ChemInform Abstract: Synthesis of Oxa and Thia Analogues of Novel Tricyclic Systems.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An efficient synthesis of bicyclic β-lactams through palladium catalysed ene–halogenocyclization

A new synthesis of oxa- and carba-cepham skeletons was developed by use of palladium catalysed ene–halogenocyclization followed by treatment with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

Isomérie Z-E des spirochromènes oxa- et thiazolidiniques-1,3 à deux atomes de carbone asymétriques. Comparaison avec les spirochromènes oxa- et thiaziniques-1,3 homologues

The synthesis of oxa- and thiazolidine-1,3 spirochromenes with two asymmetric carbon atoms in an α position to oxygen or sulphur leads generally to a mixture of two diastereoisomers for which the Z configuration is predominant. Examination of Dreiding models and application of the Karplus equation allow a good solution of this problem. On the other hand, only one isomer exists in the 2,4,5,6-tetrahydro oxa- or thiazine-1,3 homolog compounds. The study of the geometry of the aza ring proves then that the configuration may be Z or E according to whether one of the asymmetric carbon atoms is in an α or β position to oxygen or sulphur.