Ashish Verma

Malignant peripheral nerve sheath tumor of the occipital region: case report.

OBJECTIVEA rare case of a malignant peripheral nerve sheath tumor of the occipital region is presented. The role of postoperative radiotherapy in such cases is reviewed. CLINICAL PRESENTATIONA 36-year-old man presented with a small spongy swelling in the posterior aspect of the cranium since childhood. The swelling gradually increased for 2 years and then rapidly over the next 7 months. There were no associated symptoms of headache, vomiting, vertigo, focal weakness, or visual impairment. INTERVENTIONA small occipital craniectomy for total excision of the tumor was attempted. However, as a result of intracranial extension to the transverse sinus, the tumor could not be completely excised. Local radiotherapy to a dose of 59.4 Gy in 33 fractions over 6.5 weeks was delivered to the residual microscopic disease in the posterior part of the cranium. The patient has been followed up regularly for the past 28 months and continues to remain asymptomatic. CONCLUSIONAn aggressive malignant peripheral nerve sheath tumor of an atypical site such as the scalp, in which complete surgery may not always be possible, could benefit from postoperative radiotherapy. A dose of approximately 60 Gy could be effectively delivered with a satisfactory outcome.

Chiral Cadmium(II) Metal–Organic Framework from an Achiral Ligand by Spontaneous Resolution: An Efficient Heterogeneous Catalyst for the Strecker Reaction of Ketones

A thermally stable cadmium-based chiral metal-organic framework (MOF), {[Cd2(L)(H2O)(DMF)]·3DMF·2H2O}n (1; DMF = N,N-dimethylformamide), has been synthesized from an achiral ligand by spontaneous resolution. The MOF features 1D open channels with a large density of active metal sites and has a 3,6-c binodal net with a rare sit 3,6-conn topology. The metal-bound water and DMF solvents could be easily removed along with the guest molecules in the lattice upon activation to afford the desolvated framework 1. It exhibits microporous nature, as confirmed by the gas-sorption measurements with carbon dioxide uptake of 43.2 cm3 g-1 at 273 K. The open metal sites in the framework make it an outstanding heterogeneous catalyst in the Strecker reaction for the synthesis of α-aminonitriles in a solvent-free state at room temperature with excellent conversion yields.

An Amine Functionalized Metal–Organic Framework as an Effective Catalyst for Conversion of CO2 and Biginelli Reactions

A highly porous and thermally stable anionic Zn(II)-framework, {[(CH3)2NH2+]2[Zn3((μ3-O))(L)2(H2O)]·4DMF·2H2O}n (1), having exposed metal sites and pendant amine groups has been synthesized adopting the solvothermal technique. This anionic 3D framework showed two-fold interpenetration with 45.1% void volume. It has a 3,6-c binodal net with rare sit 3,6-conn topology. The metal bound aqua ligand could be easily removed along with the guest molecules in the lattice upon activation to afford the desolvated framework 1. This produced exposed metal sites that, along with the pendant amine groups incorporated in the ligand, generated a coordination space in the framework to make it an outstanding heterogeneous catalyst for the chemical fixation of CO2 with various epoxides under atmospheric pressure and in the three-component Biginelli reaction with different aldehydes, ethyl acetoacetate, and urea to afford dihydropyrimidinones.

Stereoselective synthesis of 1,2-annulated-C-Aryl glycosides from carbohydrate-derived terminally unsubstituted dienes and arynes: Application towards synthesis of sugar-fused- or branched- naphthalenes, and C-Aryl glycosides

Synthesis of 1,2-annulated-C-aryl glycosides has been achieved in a stereoselective manner through the Diels-Alder reaction between carbohydrate-derived terminally unsubstituted dienes and in situ generated arynes. In these reactions, formation of sugar-fused (or branched) naphthalenes was also observed and found to be temperature dependent and thus constituting one of the salient features of this work. The synthetic importance of 1,2-annulated-C-aryl glycosides has been explored by transforming them into densely oxygenated products by functionalizing the unsubstituted exo-double bond. Further, 1,2-annulated-C-aryl glycosides give rapid access to C-aryl glycosides in four steps.

MALIGNANT PERIPHERAL NERVE SHEATH TUMOR OF THE OCCIPITAL REGION

OBJECTIVEA rare case of a malignant peripheral nerve sheath tumor of the occipital region is presented. The role of postoperative radiotherapy in such cases is reviewed. CLINICAL PRESENTATIONA 36-year-old man presented with a small spongy swelling in the posterior aspect of the cranium since childhood. The swelling gradually increased for 2 years and then rapidly over the next 7 months. There were no associated symptoms of headache, vomiting, vertigo, focal weakness, or visual impairment. INTERVENTIONA small occipital craniectomy for total excision of the tumor was attempted. However, as a result of intracranial extension to the transverse sinus, the tumor could not be completely excised. Local radiotherapy to a dose of 59.4 Gy in 33 fractions over 6.5 weeks was delivered to the residual microscopic disease in the posterior part of the cranium. The patient has been followed up regularly for the past 28 months and continues to remain asymptomatic. CONCLUSIONAn aggressive malignant peripheral nerve sheath tumor of an atypical site such as the scalp, in which complete surgery may not always be possible, could benefit from postoperative radiotherapy. A dose of approximately 60 Gy could be effectively delivered with a satisfactory outcome.

TEMPO-Catalyzed Oxidation of 3-O-Benzylated/Silylated Glycals to the Corresponding Enones using PIFA-Water Reagent System

A simple, highly efficient and regiospecific method for the direct conversion of 3- O-benzylated as well as silylated glycals into the corresponding enones has been developed using PIFA-TEMPO and water reagent system. The reaction is scalable on a gram scale under mild conditions with a yield up to 86%.

Stereoselective synthesis of 2-deoxy-β-C-aryl/alkyl glycosides using Prins cyclization: Application in the synthesis of C-disaccharides and differently protected C-aryl glycosides

2-Deoxy-β-C-aryl/alkyl glycosides were synthesized from di-O-pivaloyl protected homoallylic alcohol derived from D-mannitol with various aldehydes via the Prins cyclization. The salient features of this methodology are high yields and excellent stereoselectivity. This method has also been successfully applied to the synthesis of differently protected 2-deoxy-β-C-aryl glycosides and C-disaccharides. One of the 2-deoxy-β-C-aryl glycosides was utilized as a glycosyl acceptor in the glycosylation to synthesize an O-linked disaccharides.