Unusual retention of isoxazole ring under the influence of 3-(substituted nitrophenyl)-2-isoxazoline during catalytic hydrogenation of isoxazoline-substituted isoxazole systems
作者:Vijay Singh、Samiran Hutait、Gaya P. Yadav、Prakas R. Maulik、Sanjay Batra
DOI:10.1002/jhet.87
日期:2009.7
The cleavage of the isoxazole ring during the Raney-Ni-promoted catalytichydrogenation is prevented under the influence of 3-(substituted nitrophenyl)-2-isoxazoline in isoxazoline-substituted isoxazole systems produced via 1,3-dipolar cycloaddition either on the Baylis–Hillman derivatives or Grignard products. Unexpectedly, the hydrogenations in these diastereomeric compounds were observed to exclusively
NaBH<sub>4</sub>-mediated FacileReduction of Esters of Baylis-Hillman Adducts: An EfficientApproach to Substituted Propane-1,3-Diols
作者:Sanjay Batra、Arundhati Patra、Amiya P. Bhaduri
DOI:10.1055/s-2003-40992
日期:——
Reduction of the ester group in the Baylis-Hillman adductsby NaBH4 reduction is facilitated by the secondary hydroxyl grouppresent at their β-position. This method is efficient forthe preparation of substituted propane-1,3-diols.
3-Aryl-5-isoxazolecarboxaldehyde undergoes fast Baylis-Hillman reaction with a variety of activated alkenes to yield the corresponding adducts in excellent yields. Some of the Baylis-Hillman adducts reported herein have been subsequently modified to obtain isoxazole substituted pyrazolin-3-ones and γ-butyrolactones.
The synthesis of isoxazole-based derivatives utilizing Baylis-Hillman chemistry and results of their preliminary bioevaluation as hypolipidemic agents in triton model are described. (C) 2003 Elsevier Science Ltd. All rights reserved.
Persistent splenomegaly in an adult female with homozygous sickle cell anemia
Sickle cell anemia (SCA) is associated with repeated episodes of erythrostasis in the spleen, which lead to thrombosis and infarction of the spleen resulting in "autosplenectomy" which is usually complete by 8 years of age.We present a case of a 22-year-old female who presented with complaints of fever, bone pain and joint swelling. On examination she had pallor, icterus and moderate splenomegaly. Her hemoglobin was 7.5g/dl. Peripheral smear showed many sickled red cells. Slide test for sickling was positive with 2% sodium metabisulphite. Hemoglobin electrophoresis revealed a single band in the hemoglobin S, D, and G region. No band was seen in the HbA & HbA(2) region. HbF level was 0%. USG showed an enlarged spleen with few defined hypoechoeic lesion.We present this case because of rarity of association of homozygous SCA with splenomegaly in this age group, the confusion that echogenic lesions in spleen can create and to emphasize the risk of sequestration crises, which remains in such cases.