scholarly journals Highly Enantioselective Synthesis of (R)-α-Alkylserines via Phase-Transfer Catalytic Alkylation of o-Biphenyl-2-oxazoline-4-carboxylic Acid tert-Butyl Ester Using Cinchona-Derived Catalysts.

ChemInform ◽  
2005 ◽  
Vol 36 (37) ◽  
Author(s):  
Yeon-Ju Lee ◽  
Jihye Lee ◽  
Mi-Jeong Kim ◽  
Taek-Soo Kim ◽  
Hyeung-geun Park ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Phase Transfer ◽  
Butyl Ester ◽  
Enantioselective Synthesis ◽  
Tert Butyl ◽  
Catalytic Alkylation

Synthesis of Optically Active Hydroxyalkyl Cycloheptatrienes: A Key Step in the Total Synthesis of 6,11-Methylene-LXB4

Synlett ◽  
2020 ◽  
Vol 32 (01) ◽  
pp. 45-50
Author(s):  
Udo Nubbemeyer ◽  
Analuisa Nava ◽  
Lukas Trippe ◽  
Andrea Frank ◽  
Lars Andernach ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Structure Elucidation ◽  
Butyl Ester ◽  
Optically Active ◽  
Chiral Hplc ◽  
Reaction Conditions ◽  
Acid Product ◽  
Tert Butyl ◽  
Nabh4 Reduction

AbstractStarting from methyl cycloheptatrienyl-1-carboxylate, 6-acylation was successfully achieved employing glutaryl chloride in the presence of AlCl3 under controlled reaction conditions to furnish keto carboxylic acid product. After protection of this keto carboxylic acid as tert-butyl ester, reagent-controlled enantioselective reductions delivered configuration-defined methyl-6-hydroxylalkyl cycloheptatriene-1-carboxylates with up to 80% ee. Whereas simple NaBH4 reduction of the keto carboxylic acid and subsequent lactonization afforded a methyl-6-tetrahydropyranonyl cycloheptatriene-1-carboxylate. Resolution using chiral HPLC delivered the product enantiomers with up to >99% ee Finally, ECD analyses enabled structure elucidation. The products are used as key intermediates in enantioselective 6,11-methylene-lipoxin B4 syntheses.

scholarly journals Crystal structure of 2-(4-allyl-4-methyl-2-oxo-1,4-dihydro-2H-benzo[d]- [1,3]oxazin-6-yl)-5-cyano-pyrrole-1-carboxylic acid tert-butyl ester, C22H23N3O4

2014 ◽  
Vol 229 (2) ◽  
pp. 127-128 ◽  
Author(s):  
Chuanhong Zhang ◽  
Jianguo Lin ◽  
Gaochao Lv ◽  
Yang Cao ◽  
Shineng Luo
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Butyl Ester ◽  
Tert Butyl

Abstract C22H23N3O4, triclinic, P1¯ (no. 2), a = 6.992(3) Å, b = 8.159(4) Å, c = 18.778(8) Å, α = 92.118(7)°, β = 93.463(7)°, γ = 101.623(7)°, V = 1045.9 Å3, Z = 2, Rgt(F) = 0.0576, wRref(F2) = 0.1778, T = 296 K.

Enantioselective Synthesis of (R)-α-Alkylhomoserines and (R)-α-Alkylhomocysteines via Phase-Transfer Catalytic Alkylation

Synlett ◽  
2009 ◽  
Vol 2009 (04) ◽  
pp. 671-674 ◽  
Author(s):  
Hyeung-geun Park ◽  
Sang-sup Jew ◽  
Taek-Soo Kim ◽  
Yeon-Ju Lee ◽  
Kyoungyim Lee ◽  
...  
Keyword(s):  
Phase Transfer ◽  
Enantioselective Synthesis ◽  
Catalytic Alkylation

ChemInform Abstract: Facile Synthesis of L-Dopa tert-Butyl Ester by Catalytic Enantioselective Phase-Transfer Alkylation.

ChemInform ◽  
2001 ◽  
Vol 32 (3) ◽  
pp. no-no
Author(s):  
Takashi Ooi ◽  
Minoru Kameda ◽  
Hidenori Tannai ◽  
Keiji Maruoka
Keyword(s):  
Phase Transfer ◽  
Butyl Ester ◽  
Facile Synthesis ◽  
Tert Butyl
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