- Chemoselective alcoholysis/acetolysis of trans-ketals over cis-ketals and its application in the total synthesis of the cellular second messenger, d-myo-inositol-1,4,5-trisphosphate
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The involvement of natural phosphoinositols in various cellular signalling processes and the use of synthetic inositol derivatives in catalysis, supramolecular chemistry, natural product synthesis etc. gave momentum to myo-inositol chemistry. The presence of six secondary hydroxyl groups necessitates efficient protection-deprotection strategies for the synthesis of inositol derivatives. An important strategy for the initial protection of myo-inositol is the di-ketalization, which gives a mixture of three diketals, each having both cis-fused and trans-fused ketals. It is important to have methodologies either to selectively hydrolyze one of the two ketals or to convert one of the two acid labile ketals to an orthogonal base labile protecting group. By exploiting the difference in strain between trans-ketals and cis-ketals, we developed two operationally simple, high yielding methodologies for the chemoselective hydrolysis/acetolysis of trans-ketals (both isopropylidene and cyclohexylidene) of inositols, leaving the cis-ketal undisturbed, using cheap and easily preparable H2SO 4-silica as the catalyst. Also, terminal ketal moieties of carbohydrates and acyclic polyols could be selectively hydrolyzed/acetolyzed leaving the internal ketals intact. The use of methanol as the solvent leads to chemoselective alcoholysis but the use of DCM and acetic anhydride leads to chemoselective acetolysis. Applying this methodology, a short synthesis of d-myo-inositol-1,4,5-trisphosphate has been achieved. The Royal Society of Chemistry.
- Vidyasagar, Adiyala,Pathigoolla, Atchutarao,Sureshan, Kana M.
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p. 5443 - 5453
(2013/09/02)
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- COMPOUNDS AND COMPOSITIONS FOR THE DETECTION AND TREATMENT OF ALZHEIMER'S DISEASE AND RELATED DISORDERS
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One aspect of the present invention relates to compounds, compositions and methods for diagnosis and/or treatment of a subject suffering from an amyloidosis-associated pathological condition. In certain embodiments, the imaging and/or therapeutic agents of the instant invention may be administered to a subject for identification and/or treatment of amyloid deposits. A specific imaging method detects amyloid deposits by administering the imaging agent to the subject and detecting the spatial distribution of the agent. Differential accumulation of the agent is indicative of AD or an amyIoidosis-associated pathological condition and can be monitored by using a PET or SPECT camera.
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Page/Page column 66
(2009/10/22)
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