An expedient synthesis of tetrakis (cyclopropylmethyl) methane

Synthesis of tetrakis(cyclopropylmethyl)methane, a new symmetric product has been described using the radical mediated gem-diallylation of cyclopropylmethyl xanthate as a key step and its single crystal X-ray analysis established its C2-symmetry

RF Controlled Robotic Vehicle with Metal Detection Project

The project is intended to cultivate a robotic vehicle that can sense metals ahead of it on its path similar to detecting land mines. The robot is controlled by a remote using RF technology. It consists of a metal detector circuit interfaced to the control unit that alarms the user behind it about a doubted land mine ahead. An 8051 series of microcontroller is used for the preferred operation. For controlling the movement of robot either to forward, backward & right or left commands are sent to the receiver by using push buttons of the transmitter. At the receiving end two motors are interfaced to the microcontroller where they are used for the movement of the vehicle. The RF transmitter acts as a RF remote control that has the advantage of sufficient range (up to 200 meters) with proper antenna, while the receiver decodes before serving it to another microcontroller to drive DC motors via motor driver IC for necessary work. A metal detector circuit is attached on the robot body and its operation is carried out automatically on sensing any metal underneath. The instant the robot senses this metal it produces an alarm sound through buzzer. This is to aware the operator of a probable metal (eg: land mine) ahead on its path. Further the project can be enhanced by mounting a wireless camera on the robot so that the operator can govern the movement of the robot remotely by observing it on a screen

Retentive Aids in Maxillofacial Prosthodontics - A Review.

Retention has always been a problem in prosthodontics. Prosthodontists have always been struggling with retention in a maxillofacial prosthesis . Increased retention improves comfort as well as the confidence in the patient while wearing a facial prosthesis at work and in social settings. Advances in techniques used for retention of maxillofacial prosthesis and the materials used have been remarkable in the past several years. The journey from using metal bands to using adhesives to placing implants for retaining a maxillofacial prosthesis has been fascinating and satisfying to many, but, the aim of achieving the full potential still remains incomplete. &nbsp

A simple and practical approach to enantiomerically pure (S)-3-hydroxy-γ-butyrolactone: synthesis of (R)-4-cyano-3-hydroxybutyric acid ethyl ester

The oxidation of α- or β-(1,4) linked disaccharides or oligosaccharides with cumene hydroperoxide in the presence of a base gave (S)-3,4-dihydroxybutyric acid, which was cyclized under acidic conditions to furnish (S)-3-hydroxy-γ-butyrolactone. This was subsequently converted into (R)-cyano-3-hydroxybutyric acid ethyl ester, an intermediate for statin based drugs and other related compounds

Diastereoselective reformatsky reaction of methyl 4-bromocrotonate with 1,2:5, 6-di-O-isopropylidene-[α]-D-ribo-hexofuranos-3-ulose: application to novel

This paper describes an efficient synthetic route for novel bicyclic nucleosides. The stereochemistry of the targeted bicyclic nucleosides was successfully achieved by vinylogous Reformatsky reaction and ring closing metathesis reaction on a carbohydrate backbone

Eco-friendly dyeing of cotton fabric with tender green coconut soft husk

AbstractTender coconut husk, a waste after consuming the coconut water, has been explored as a dye for the colouration of cotton fabric. It is abundant in polyphenolic compounds which are the main coloring agent. The aqueous extraction method is used for obtaining the dye. Different mordanting techniques, such as pre-mordanting, simultaneous mordanting and post mordanting, are used to dye cotton fabric. Tannic acid and alum are used as primary mordants, and ferrous sulphate and copper sulphate are used as secondary mordants. A range of shades is obtained by varying mordants and different mordanting methods. Overall fastness properties of these shades are found good. Dyed fabrics are also found to have an excellent UV protection property

Palladium mediated cycloisomerization of sugar alkynols: Synthesis of cyclic enol-ethers and spiroketals

Functionalized bicyclic enol-ethers and spiroketals are prepared by Pd catalyzed cycloisomerization of 3-C-alkynylfuranosyl derivatives. Cycloisomerization of differently substituted alkyne derivatives revealed a preference for 6-endo-dig cyclization over 5-exo-dig if the substituent is not sufficiently electron withdrawing. The scope of these cycloisomerizations has been further extended by integrating with conjugate addition

Synthesis of new chiral 4,5,6,7-tetrahydro [1,2,3] triazolo [1,5-a] pyrazines from α-amino acid derivatives under mild conditions

A practical and efficient regioselective synthesis of several new chiral 4,5,6,7-tetrahydro[1,2,3]triazolo[1,5-a]pyrazines is described from α -amino acid derivatives following intramolecular 'click' reaction as the key step. The method obviates product -purification; to obtain the pure triazole products, only the solvent needs to be evaporated

A double suzuki approach for synthesis of substituted diarylmethylidenefluorenes

A convenient synthesis of substituted diarylmethylidenefluorene derivatives, using a double Suzuki reaction, is reported