α-alkylation of serine with self-reproduction of the center of chirality
作者:Dieter Seebach、Johannes D. Aebi
DOI:10.1016/s0040-4039(01)81227-2
日期:1984.1
The lithiumenolate 6 of methyl (2R,4S)-2--butyl-3-formyl-oxazolidine-4-carboxylate (4b) derived from (s)-(+)-serine can be generated with LDA in THF solution at −75°C. Alkylations (→ 9) and hydroxyalkylations (→ 10, 11) occur preferentially (>95:5) from the Re-face of the donor center (relative topicity lk). This stereochemical course is derived from the absolute configuration of 2-deuterio- and 2-methyl-serine
Synthesis, stereochemical determination and biochemical characterization of the enantiomeric phosphate esters of the novel immunosuppressive agent FTY720
作者:Jeffrey J. Hale、Lin Yan、William E. Neway、Richard Hajdu、James D. Bergstrom、James A. Milligan、Gan-Ju Shei、Gary L. Chrebet、Rosemary A. Thornton、Deborah Card、Mark Rosenbach、HughRosen、Suzanne Mandala
DOI:10.1016/j.bmc.2004.07.020
日期:2004.9
The novel immunosuppressive agent FTY720 (1) is phosphorylated in vivo in a variety of species yielding an active metabolite that is an agonist of four of the five known G-protein-coupled sphingosine-1-phosphate (S1P) receptors. A synthesis amenable to producing gram quantities of the stereoisomeric phosphate esters, a determination of their absolute stereochemistry via an enantioselective synthesis
New fast and practical method for the enantioselective synthesis of α-vinyl, α-alkyl quaternary α-amino acids
作者:Marcello Di Giacomo、Valerio Vinci、Massimo Serra、Lino Colombo
DOI:10.1016/j.tetasy.2007.12.012
日期:2008.2
We describe a fast and practical enantioselective synthesis of (S)-N-Cbz-alpha-vinyl, phenylalanine, suitable for the preparation of different N-Cbz-alpha-vinyl aminoacids of both configurations. The new protocol exploits a Wittig reaction on highly enantiomeric enriched N-Cbz-alpha-formyl-alpha-alkyl amino esters, readily accessible from (L)-serine through a stereoselective alkylation of Seebach's oxazolidine, carried out with a significant improvement of the previously reported method. The synthetic scheme is suitable for gram scale preparation of the desired product with a 94% ee. (C) 2008 Elsevier Ltd. All rights reserved.
Stereoselective synthesis of amino-substituted apio dideoxynucleosides through a distant neighboring group effect
作者:Won Jun Choi、Hee Sung Ahn、Hea Ok Kim、Sanghee Kim、Moon Woo Chun、Lak Shin Jeong
DOI:10.1016/s0040-4039(02)01295-9
日期:2002.8
Novel amino-substituted apio nucleoside (2R,4R)-LJ-45 as a potential anti-HBV agent was stereoselectively synthesized from the known oxazolidine 1 through a distant neighboring group effect. It is believed that this synthetic method using a chiral template, (-)-L-serine methyl ester can be generally applied to the synthesis of other chiral amino-substituted nucleosides. (C) 2002 Elsevier Science Ltd. All rights reserved.