- Synthesis of (2S,4S)-4-hydroxyproline from D-glucose
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Diacetone-D-glucose 1 gives 3-O-methylxanthate 2 on reaction with NaH=Me I. Reductive deoxygenation of compound 2 by Bu3SnH gives the corresponding 3-deoxy glucose derivative 3 and on acid-catalyzed regioselective deprotection of C-5,6-acetonide gives the diol 4. The diol on oxidative cleavage with NaIO4 gives the aldehyde 5, which on further condensation with benzylamine followed by reduction with NaBH4 gives the amine 7. Z-Protection of the amine followed by methanolysis gives methyl furanoside 9. Reaction of 9 with methanesulfonyl chloride=Et3N gives the corresponding C-3-O-mesylate derivative 10. Catalytic hydrogenation of compound 10 (Pd=C=H2=MeOH 3 kg) gives bicyclic oxaazo compound 11, due to deprotection of the N-benzyl- and Z-protecting groups and intramolecular nucleophilic displacement of the C-2-O-mesylate by the C-5 amine in a one-pot reaction. Z-Protection of the amine 11 followed by acid-catalyzed hydrolysis gives acetal 13. Reduction of acetal by use of NaBH4 gives Z-prolinol 14. Selective oxidation of diol 14 by (2,2,6,6-tetramethylpiperidin-1-yl)-oxyl (TEMPO)=[(bis)(acetoxy)iodo]-benzene (BAIB) and NaClO2=NaH 2PO4, followed by Z-deprotection, gives the title compound I in 3.5% overall yield from D-glucose. Copyright Taylor & Francis Group, LLC.
- Mereyala, Hari Babu,Pathuri, Gopal,Nagarapu, Lingaiah
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p. 1278 - 1287
(2012/04/17)
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- VLA-4 INHIBITORY DRUG
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There is provided a VLA-4 inhibitory drug having good oral absorbability and exhibiting sufficient anti-inflammatory effects when administered orally. A compound represented by the following formula (I): wherein R1 represents a hydrogen atom or a C1-8 alkyl group; R2 represents a hydrogen atom, a halogen atom, a C1-8 alkoxy group, orabenzyloxygroupwhichmaybe substituted; Q represents a monocyclic or bicyclic nitrogen-containing heterocyclic group which may be substituted, and has a nitrogen atom as the bonding site; Y represents an oxygen atom or CH2; W represents a bicyclic aromatic hydrocarbon ring group which may be substituted, or a bicyclic aromatic heterocyclic group whichmaybe substituted; R3a, R3b and R3c each independently represent a hydrogen atom, a halogen atom, a C1-8 alkoxy group or a C1-8 alkyl group; and A1 represents a nitrogen atom or C-R3d (wherein R3d represents a hydrogen atom, a halogen atom, a C1-8 alkoxy group or a C1-8 alkyl group), or a salt thereof, or a VLA-4 inhibitory drug comprising the compound or the salt as an active ingredient.
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Page/Page column 108
(2008/12/08)
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- Carboxy mediated stereoselective reduction of ketones with sodium triacetoxyborohydride: Synthesis of novel 3,4-fused tetrahydropyran and tetrahydrofuran prolines
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In the presence of a carboxyl group positioned for participation, NaBH(OAc)3 will reduce the usually unreactive ketones in a stereoselective manner. This reaction was applied in a key step to prepare precursors 7 and 15 toward the title compounds 1 and 2. These results are consistent with the exchange of one of the acetoxy groups in the reducing agent with the carboxy group followed by intramolecular delivery of the hydride.
- Liu, Yi-Tsung,Wong, Jesse K.,Tao, Meng,Osterman, Rebecca,Sannigrahi, Mousumi,Girijavallabhan, Viyyoor M.,Saksena, Anil
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p. 6097 - 6100
(2007/10/03)
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- Synthesis and biological evaluation of nonpeptide integrin antagonists containing spirocyclic scaffolds
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Analogues of isoxazoline αvβ3 antagonist 1 designed to further restrict the four carbon alkyl tether were prepared by incorporating two spirocyclic scaffolds, 1-oxa-2-azaspiro[4,5]dec-2-ene and 1-oxa-2,7-diazaspiro[4,4]non-2-ene. Additional optimization provided potent antagonists of both αvβ3 and α 5β1 which are selective over GPIIb/IIIa.
- Smallheer, Joanne M.,Weigelt, Carolyn A.,Woerner, Francis J.,Wells, Jennifer S.,Daneker, Wayne F.,Mousa, Shaker A.,Wexler, Ruth R.,Jadhav, Prabhakar K.
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p. 383 - 387
(2007/10/03)
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- Nucleosides and Oligonucleotides Derived from trans-4-Hydroxy-N-acetylprolinol
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The 4-O-phosphoramidites of monomethoxytritylated 4-hydroxy-N-6-benzoyladenin-9-yl)acetyl>prolinol and 4-hydroxy-N-prolinol were prepared for incorporation into nucleic acids.The L-trans all-adenine oligonucleotide (ON) hybridises to natural oligothymidylate, apparently via triplex formation.All-purine sequences of the L-trans form can also form homo-complexes with their pyrimidine counterpart.The D-trans compounds give larger destabilisation when inserted in DNA.D-trans all-adenine ONs do not form complexes with natural oligothymidylate.For this series of modified ONs no hybridisation could be detected between complementary strands of opposite enantiomeric form.
- Ceulemans, G.,Aerschot, A. Van,Herdewijn, P.
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p. S234 - S237
(2007/10/03)
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