Concise and Straightforward Asymmetric Synthesis of a Cyclic Natural Hydroxy-Amino Acid
نویسندگان
چکیده
منابع مشابه
Concise and straightforward asymmetric synthesis of a cyclic natural hydroxy-amino acid.
An enantioselective total synthesis of the natural amino acid (2S,4R,5R)-4,5-di-hydroxy-pipecolic acid starting from D-glucoheptono-1, 4-lactone is presented. The best sequence employed as a key step the intramolecular nucleophilic displacement by an amino function of a 6-O-p-toluene-sulphonyl derivative of a methyl D-arabino-hexonate and involved only 12 steps with an overall yield of 19%. The...
متن کاملThe asymmetric synthesis of chiral cyclic α-hydroxy phosphonates and quaternary cyclic α-hydroxy phosphonates.
A highly practical, catalytic enantioselective cyclic phosphite addition to aldehydes and ketones was developed. The reaction rate of the asymmetric hydrophosphonylation was significantly enhanced by the addition of silver carbonate. Particularly, significant improvement has been achieved on the asymmetric hydrophosphonylation of unactivated ketones, giving quaternary α-hydroxy phosphonates wit...
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Derivatives of the two unusual 8-hydroxy amino acids in echinocandin D (1) have been synthesized by employing asymmetric glycine enolate aldol methodology. The N-Boc,O-benzyl derivative of (2S,3R)-3-hydroxyhomotyrosine (Hht) (2) and the methyl ester of (2.9,3S,4.9)-3-hydroxy-4-methylproline (Hmp) (3) have been synthesized in four steps each from (isothiocyanoacety1)oxazolidinone 4 and (bromoace...
متن کاملStraightforward synthesis of cyclic and bicyclic peptides.
Cyclic peptide architectures can be easily synthesized from cysteine-containing peptides with appending maleimides, free or protected, through an intramolecular Michael-type reaction. After peptide assembly, the peptide can cyclize either during the trifluoroacetic acid treatment, if the maleimide is not protected, or upon deprotection of the maleimide. The combination of free and protected mal...
متن کاملA concise asymmetric total synthesis of aspidophytine.
An expedient asymmetric total synthesis of aspidophytine is reported. A highly convergent strategy involving the sequential annulation of vinyl iodide 5 with indole 6 exploits varying modes of indole reactivity to provide aspidophytine in 23% over six steps from 5.
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ژورنال
عنوان ژورنال: Molecules
سال: 2014
ISSN: 1420-3049
DOI: 10.3390/molecules191219516