Asymmetric Cascade Dearomatization-Cyclization Reaction of Tryptamines with ß,γ-Alkynyl-α-imino Esters: Access to Hexahydropyrrolo[2,3-b]indole-Containing Tetrasubstituted α-Amino Allenoates.

An organocatalytic enantio- and diastereoselective synthesis of hexahydropyrrolo[2,3-b]indole-containing tetrasubstituted α-amino allenoates, exhibiting both axial and central chirality, has been accomplished via cascade dearomatization-cyclization reaction. The γ-addition to ß,γ-alkynyl-α-imino esters provides a library of densely substituted highly enantioenriched allenes in high yields and excellent stereoselectivities. In addition, the scope of this methodology has been extended to tryptophol as well. A scale-up reaction and synthetic transformations of the products were performed to demonstrate the practical usefulness of this approach.

Organocatalytic Asymmetric Cascade Michael-Acyl Transfer Reaction between 2-Fluoro-1,3-diketones and 2-Hydroxynitrostyrenes.

An organocatalytic asymmetric cascade Michael-acyl transfer reaction of 2-hydroxynitrostyrenes and monofluorinated ß-diketones has been developed employing a cooperative catalytic system. A combination of quinine-derived bifunctional squaramide catalyst and achiral hydrogen bond donor cocatalyst was found to be the most effective for this reaction and provided the fluorinated acyl transfer products in high yields with good diastereo- and excellent enantioselectivities. Synthetic transformations have been demonstrated, including the synthesis of functionalized 2,3-dihydrobenzofurans and 1-pyrroline.

Aetiology and diagnostic utility of serum ascites albumin gradient in children with ascites.

BACKGROUND: Ascites in children is multifactorial and serum ascites albumin gradient (SAAG) ≥1.1 helps differentiate portal hypertension (PHTN) related from non-PHTN ascites. AIMS: We evaluated the aetiology and diagnostic accuracy of SAAG in children with ascites. METHODS: Children with ascites were retrospectively evaluated. Etiological diagnosis was based on clinical presentation and investigations. All cases with ascitic fluid analysis and a definite diagnosis were included for calculating the utility of SAAG. RESULTS: We enrolled 878 children (568[64.7%] boys). Majority were PHTN related (638[72.7%]) and secondary to acute viral hepatitis (98,15.4%), acute liver failure (185,29%), chronic liver disease (276,43.3%) and Budd-Chiari syndrome (79,12.4%). Other causes included tubercular (46,5.2%), pancreatic (32,3.6%), chylous (20,2.3%), biliary (12,1.4%), pseudoascites (16,1.8%), infections (46,5.2%), nephrotic (26,2.9%), malignancy (23,2.6%), cardiac (9,1.0%) and others (10,1%). SAAG (n = 305) correctly differentiated PHTN and non-PHTN ascites in 272 (89.2%) cases, with a high sensitivity (97%), specificity (93%) and diagnostic accuracy (95.8%). Reasons for inaccurate SAAG included mixed ascites (n = 9), different day serum and ascitic fluid albumin estimation (n = 5), serum albumin ≤1.1 g/dL (n = 2), chylous ascites (n = 3), hypergammaglobulinemia (n = 1), albumin infusions (n = 1) and unexplained (n = 12). CONCLUSIONS: Nearly 27% children had non-PHTN related ascites. SAAG differentiates PHTN from non-PHTN ascites with a diagnostic accuracy of 95%.