- Solution-phase automated synthesis of an α-amino aldehyde as a versatile intermediate
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A solution-phase automated synthesis of the versatile synthetic intermediate, Garner's aldehyde, was demonstrated. tert-Butoxycarbonyl (Boc) protection, acetal formation, and reduction of the ester to the corresponding aldehyde were performed utilizing our originally developed automated synthesizer, ChemKonzert. The developed procedure was also useful for the synthesis of Garner's aldehyde analogues possessing fluorenylmethyloxycarbonyl (Fmoc) or benzyloxycarbonyl (Cbz) protection.
- Masui, Hisashi,Yosugi, Sae,Fuse, Shinichiro,Takahashi, Takashi
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supporting information
p. 106 - 110
(2017/02/15)
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- Synthesis and growth inhibitory activity of chiral 5-hydroxy-2-N-acyl-(3E)-sphingenines: Ceramides with an unusual sphingoid backbone
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The unusual sphingoid base 5-hydroxy-3-sphingenine was identified in the hydrolysate of brain sphingolipids more than 40 years ago. We present here the first synthesis of the 5R and 5S diastereoisomers of the N-acyl derivatives of 5-hydroxy-3-sphingenine, 2 and 3, respectively, which represent regioisomers of (2S,3R)-ceramide (1). The key steps include the synthesis of a,β-unsaturated ketone intermediates 4 and 5 from N-Cbz- and N-Boc -L-serine and diastereoselective reduction of the enones. The configuration at the new carbinol center was deduced by proton NMR analysis of (R)- and (S)-Mosher [methoxy(trifluoromethyl)phenylacetate] ester derivatives. Ceramide analogues 2 and 3 showed a markedly higher antiproliferative activity than 1 on MCF-7 cells.
- Chun, Jiong,Byun, Hoe-Sup,Arthur, Gilbert,Bittman, Robert
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p. 355 - 359
(2007/10/03)
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- Homochiral 4-azalysine building blocks: Syntheses and applications in solid-phase chemistry
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Anomalous amino acids not only play central roles as mimics of natural amino acids but also offer opportunities as unique building blocks for combinatorial chemistry. This paper describes the chiral syntheses and solid-phase applications of a versatile atypical amino acid, 4-azalysine (2,6-diamino-4-azahexanoic acid) 1. The syntheses of differentially protected 4-azalysine derivatives 28a-e have been developed by two efficient and inexpensive routes that start either from Garner's aldehyde 16 or the chiron (S)-Nα-Cbz-2,3-diaminopropionic acid 23. Both approaches employ the convergent modular concept and exploit reductive amination of aldehydes with amines as the key step for the fusion of the two segments. In the first route, the overall process inverts the chirality of the starting material, L-serine, and thus provides an excellent route to the unnatural D-isomers. The alternative route starting from L-asparagine provides a shorter and high-yielding route to orthogonally protected 4-azalysine derivatives. The corresponding N2-Fmoc-4-azalysines 31a-e, readily derived from the key intermediate 27, are compatible with the Fmoc-based solid-phase peptide synthesis (SPPS) and solid-phase organic chemistry (SPOC) protocols. Furthermore, the utility and versatility of another key structure, tris-Boc-4-azalysine 2 in the engineering of novel high-loading dendrimeric polystyrene resins 33 and 36, have been demonstrated. Following derivatization with the Rink amide linker 34, the stability and robustness of these resin-bound dendrimers 35 and 37 in the synthesis of small molecules using a range of reaction conditions (e.g., Mitsunobu and Suzuki reactions) have been effectively illustrated.
- Chhabra, Siri Ram,Mahajan, Anju,Chan, Weng C.
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p. 4017 - 4029
(2007/10/03)
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- Useful synthesis of the main dehydrohexapeptide segment of a macrocyclic antibiotic, berninamycin B
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The useful synthesis of tetradehydrohexapeptide segment 2, which is the main skeleton of a macrocyclic antibiotic, berninamycin B, was first achieved. The skeleton 2 is constructed, in turn, of 2-[(Z)-1-amino-1-propenyl]-5-methyl-oxazole-4-carboxylic acid, α-dehydroalanine (ΔAla), L-Val, 2-[1-amino-1-ethenyl]-5-methyloxazole-4-carboxylic acid residues, besides L-Thr and ΔAla at the N- and C-termini, respectively.
- Yamada, Takahiro,Okumura, Kazuo,Yonezawa, Yasuchika,Shin, Chung-Gi
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p. 102 - 103
(2007/10/03)
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- Stereoselective synthesis of differentially protected derivatives of the higher amino sugars destomic acid and lincosamine from serine and threonine
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The aminoheptose destomic acid (3.5) and the aminooctose lincosamine (6.8) were synthesized in protected form by parallel sequences starting from the oxazolidine derivatives 2.4 and 5.1 of N-CBz serinal and N-BOC threoninal. The parallel sequences feature
- Marshall, James A.,Beaudoin, Serge
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p. 581 - 586
(2007/10/03)
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- Enantiospecific synthesis of (R)- and (S)-2,3-diaminopropanol from L- and D-serine
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Both chiral forms of 2,3-diaminopropanol (6) have been prepared in a convenient 5-step synthesis based on the readily available N-benzyloxycarbonyl derivatives of the methyl esters of L- and D-serine.
- Demirci, Fatih,Haines, Alan H.,Jia, Chunhua,Wu, Di
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p. 189 - 191
(2007/10/03)
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- Convenient preparation of O-benzyl-N-Cbz-D-serinol, an intermediate in β-hydroxy-α-amino acid synthesis
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A convenient preparation of (2S)-3-benzyloxy-2-[(benzyloxycarbonyl)amino]propanol (2) in 52% yield, employing cheap L-serine as starting material, is described. Conversion of 2 into methyl (2Z,4R)-5-benzyloxy-4-[(benzyloxycarbonyl)amino]pent-2-enoate (1) is reported.
- Monache,Di Giovanni,Maggio,Misiti,Zappia
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p. 1155 - 1158
(2007/10/02)
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- New Synthetic Methodology for the Synthesis of 7-Substituted Tetrahydroazepin-2-ones
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The Claisen rearrangement of the vinyl substituted ketene aminals 2 (R = CH2CHMe2, CH2OSit-BuMe2) which were generated in situ by selenoxide elimination of the aminal precursors 3 in the presence of 1,8-diazabicycloundec-7-ene (DBU) furnished the enantiomerically pure 7-substituted tetrahydroazepin-2-ones 1.
- Evans, P. Andrew,Holmes, Andrew B.,Russell, Keith
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p. 3397 - 3410
(2007/10/02)
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- Convenient preparation of (R)- and (S)-1-(2-amino-3-iodo)propanol derivatives from (S)-serine: Application in radical addition reactions
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An efficient three step synthesis of the (R)- and (S)-1-(2-amino-3-iodo)propanol derivatives 4 and 7 from (S) serine is proposed. Their use in radical reactions is illustrated.
- Maria,Da Silva,Fourrey,Machado,Robert-Gero
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p. 3301 - 3302
(2007/10/02)
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- Chiral ligands containing heteroatoms; 12. Synthesis of optically active 2-amino-2-(2'-pyridyl)-1-alkanols from β-hydroxy-α-amino acids
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The synthesis of a new class of optically active ligands such as the title compounds is presented. All the multistep procedures adopted start by the conversion of L-serine and L-threonine into the proper 2,2-dimethyloxazolidines, followed by transformatio
- Cossu,Conti,Giacomelli,Falorni
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p. 1429 - 1432
(2007/10/02)
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- A New Peptide Bond Surrogate: 2-Isoxazoline in Pseudodipeptide Chemistry
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The isoxazoline ring has been incorporated as a new peptide bond surrogate into pseudodipeptide.An easy and versatile general method for the preparation of pseudodipeptides is described.
- Kim, Byeang Hyean,Chung, Yong Jun,Keum, Gyochang,Kim, Jaheon,Kim, Kimoon
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p. 6811 - 6814
(2007/10/02)
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- SYNTHESIS OF THE HOMOCHIRAL "TRICYCLIC HEART" OF MANZAMINE A
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An expedient and enantiospecific synthesis of a strategically functionalized tricyclic intermediate for the construction of manzamine A is described.
- Brands, Karel M. J.,Meekel, Arthur A. P.,Pandit, Upendra K.
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p. 2005 - 2026
(2007/10/02)
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- Synthesis of an optically active tricyclic intermediate for manzamines
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L-Serine has been converted into a chiral pyrroloisoquinoline derivative which can serve as a potential intermediate for manzamines.
- Brands, Karel M.J.,Pandit, Upendra K.
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p. 257 - 261
(2007/10/02)
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- ENANTIOSPECIFIC SYNTHESIS OF D-α,ω-DIAMINOALKANOIC ACIDS
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An enantiospecific synthesis of D-Nω-Boc-α, ω-diaminoalkanoic acids starting from L-serine is described.
- Beaulieu, Pierre L.,Schiller, Peter W.
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p. 2019 - 2022
(2007/10/02)
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