Solitary Extramedullary Plasmacytoma of Nasal Cavity.

Solitary extramedullary plasmacytoma (SEP) of the nasal cavity is a rare neoplastic condition characterized by the localized proliferation of abnormal plasma cells. We present a case of SEP involving the nasal cavity in a 40-year-old male patient who presented with nasal obstruction and recurrent epistaxis. The diagnosis was confirmed through clinical evaluation, imaging studies, and histopathological examination of excised specimen. The patient underwent trans-nasal endoscopic excision of nasal mass without any adjuvant therapy, which resulted in successful local control. This case report highlights the clinical presentation, diagnostic approach, treatment modalities, and favourable prognosis associated with solitary extramedullary plasmacytoma of the nasal cavity.

Rapid Arene Triazene Chemistry for Macrocyclization.

Here, we report a novel rapid arene triazene strategy for the macrocyclization of peptides that generates an inbuilt chromophoric triazene moiety at the site of cyclization within a minute. The rapid arene triazene chemistry is chemoselective for secondary amines and p-amino phenylalanine. Importantly, the resulting triazene cyclic peptide is highly stable at neutral pH and under harsh conditions but rapidly responds to various external stimuli such as UV radiations and acidic conditions, resulting in the ring opening to generate the linear peptides in an unchanged form, which further cyclizes under neutral pH conditions. This method works with completely unprotected peptides and has been applied for the synthesis of 18- to 66-membered monocycles and bicycles with various amino acid compositions in one pot under neutral pH conditions. Due to the high stability of triazene cyclic peptides, the postcyclization modification was carried out with various functional groups. This rapid, macrocyclization strategy featuring a triazene scaffold, amenable to late-stage diversification and responsive to external stimuli, should find application in various fields of chemical biology, selective drug delivery, and identification of cyclic peptide hits after library screening.

Synthesis of di- and trihydroxy proline derivatives from D-glycals: Application in the synthesis of polysubstituted pyrrolizidines and bioactive 1C-aryl/alkyl pyrrolidines.

Six different types of O-benzyl protected proline derivatives have been synthesized from D-glycals and 2C-formyl-glycals. One of the di-O-benzyl protected proline derivatives has been utilized for the synthesis of polysubstituted pyrrolizidines via [3 + 2] cycloaddition in a stereoselective manner. Further, we also report on the stereoselective synthesis of biologically active 1C-aryl/alkyl pyrrolidines i.e. 4-epi-radicamine B, 4-epi-radicamine A, 1C-butyl and 1C-methyl pyrrolidines through double reductive amination of a variety of D-glucal derived diketones with p-methoxybenzylamine.

Palladium catalyzed synthesis of sugar-fused indolines via C(sp2)-H/NH activation.

A simple Pd(OAc)2 catalyzed strategy for the synthesis of sugar-fused indolines from 2-N-oxalylamido-2-deoxy-C-aryl glycosides is reported by utilizing N-oxalylamido group as an auxiliary via C(sp2)-H/NH Activation. The reaction is successfully applied on glucose as well as galactose derived differently substituted 2-N-oxalylamido-2-deoxy-C-aryl glycosides to give sugar-fused indolines in moderate to good yields. The utility of this strategy in the synthesis of sugar-fused indoles is also described.

Stereoselective synthesis of sugar-fused (or 1,2-annulated) isochromans and isochromanones by using oxa-Pictet-Spengler reaction.

A highly efficient stereoselective synthesis of sugar fused 1,2-annulated isochromans is reported by utilizing the oxa-Pictet-Spengler cyclization reaction. The process is found to be very general as both glucal and galactal derived C2-hydroxy-α-C-aryl glycosides lead to the target molecules in good yields. The utility of this strategy was extended to the synthesis of sugar fused isochromanones, which are bergenin type molecules.

TEMPO-Catalyzed Oxidation of 3- O-Benzylated/Silylated Glycals to the Corresponding Enones Using a 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-ß-C-aryl/alkyl glycosides using Prins cyclization: Application in the synthesis of C-disaccharides and differently protected C-aryl glycosides.

2-Deoxy-ß-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-ß-C-aryl glycosides and C-disaccharides. One of the 2-deoxy-ß-C-aryl glycosides was utilized as a glycosyl acceptor in the glycosylation to synthesize an O-linked disaccharides.

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.