- Efficient preparation of biologically important 1,2-amino alcohols
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An efficient three-step methodology developed for the preparation of 1,2-amino alcohols. In the first step a rapid coupling between bromoketones and potassium phthalimide in ionic liquid produced-phthalimido ketones in quantitative yields, which is followed by a facile reduction using NaCNBH 3 in acetic acid to give corresponding phthalimido alcohols and finally effecting hydrazinolysis in water at 60C to yield biologically important 1,2-amino alcohols.
- Gupta, Pankaj,Rouf, Abdul,Shah, Bhahwal A.,Mukherjee, Debaraj,Taneja, Subhash C.
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p. 505 - 519
(2013/01/15)
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- Total synthesis of the amino hip analogue of didemnin A
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Disclosed is a synthetic method for the preparation of analogs of Didemnin A (1), particularly the Amino-Hip analog of Didemnin A, also known as “AipDidemnin A” (8). These compounds have the following structures:
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- ENANTIOSPECIFIC AND DIASTEREOSELECTIVE SYNTHESIS OF ANTI α-HYDRAZINO- AND α-AMINO-β-HYDROXYACIDS THROUGH "ELECTROPHILIC AMINATION" OF β-HYDROXYESTERS
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β-Hydroxyesters 1a-d were transformed into corresponding dianions and condensed with di-t-butylazodicarboxylate to give anti protected α-hydrazino-β-hydroxyesters 2a-d with good diastereoselectivities (up to 94:6).Cleavage of protecting groups followed by ester hydrolysis gave the previously unknown anti α-hydrazino-β-hydroxyacids 4a-d, which were in turn converted by hydrogenolysis into anti α-amino-β-hydroxyacids 5a-d.Starting from (S) 1a, enantiomerically pure (2S,3S) allo-threonine 5a was obtained in good overall yields.On the contrary, reaction of silyl ketene acetal 10, derived from 1a, with a diazonium salt furnished predominantly the syn isomer, but in unsatisfactory yield.
- Guanti, Giuseppe,Banfi, Luca,Narisano, Enrica
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p. 5553 - 5562
(2007/10/02)
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