138797-71-4

Basic information

• Product Name: Fmoc-O-tert-butyl-D-threonine
• Synonyms: FMOC-O-TERT-BUTYL-D-THREONINE;FMOC-O-T-BUTYL-D-THREONINE;FMOC-D-THREONINE(O-T-BUTYL);FMOC-D-THR(TBU)-OH;FMOC-D-THR(BUT);FMOC-D-THR(BUT)-OH;FMOC-D-THREONINE(TBU)-OH;9-FLUORENYLMETHOXYCARBONYL-O-T-BUTYL-D-THREONINE
• CAS NO: 138797-71-4
• Molecular Formula: C23H27NO5
• Molecular Weight: 397.46
• Product Categories: Amino Acids;Threonine [Thr, T];Fmoc-Amino Acids and Derivatives;Fmoc-Amino acid series
• Mol File: 138797-71-4.mol
• Article Data: 19

Chemical Properties

• Melting Point: ~130 °C
• Boiling Point: 581.7 °C at 760 mmHg
• Flash Point: 305.6 °C
• Appearance: Pale yellow/Powder
• Density: 1.197 g/cm³
• Vapor Pressure: 2.24E-14mmHg at 25°C
• Refractive Index: 1.568
• Storage Temp.: 2-8°C
• Solubility: soluble in Methanol
• PKA: 3.42±0.10(Predicted)
• BRN: 8796152
• CAS DataBase Reference: Fmoc-O-tert-butyl-D-threonine(CAS DataBase Reference)
• NIST Chemistry Reference: Fmoc-O-tert-butyl-D-threonine(138797-71-4)
• EPA Substance Registry System: Fmoc-O-tert-butyl-D-threonine(138797-71-4)

Safety Data

• WGK Germany: 3
• F: 10
• Hazardous Substances Data: 138797-71-4(Hazardous Substances Data)

Usage

Chemical Properties

white to light yellow crystal powde

Uses

O-(1,1-Dimethylethyl)-N-[(9H-fluoren-9-ylmethoxy)carbonyl]-D-threonine is a reagent used in developing CNS active opioid glycopeptides which are potential drug candidates that penetrate the blood-brain barrier to produce potent central effects.

InChI:InChI=1/C23H27NO5/c1-14(29-23(2,3)4)20(21(25)26)24-22(27)28-13-19-17-11-7-5-9-15(17)16-10-6-8-12-18(16)19/h5-12,14,19-20H,13H2,1-4H3,(H,24,27)(H,25,26)/t14-,20+/m0/s1

Upstream product

• 28920-43-6 (fluorenylmethoxy)carbonyl chloride 
• 1254943-38-8 C₈H₁₇NO₃*ClH 
• 82911-69-1 N-(9H-fluoren-2-ylmethoxycarbonyloxy)succinimide 
• 201353-89-1 O-tert-butyl-L-allo-threonine 
• 67-56-1 methanol 
• 72-19-5 L-threonine 
• 115-11-7 isobutene 
• 125760-27-2 N-(9-fluorenylmethyloxycarbonyl)-L-threonine phenacylester 
• 73731-37-0 Fmoc-Thr-OH 
• 132776-34-2 O-tert-Butyl-L-threonine Methyl Ester p-Toluenesulfonate 
• 4378-13-6 (O-tert-butyl)-L-threonine 
• 102774-86-7 9-fluorenylmethyl N-succinimidyl carbonate 
• 130674-54-3 (2R,3R)-2-N-(9-fluorenylmethyloxycarbonyl)-D-allothreonine 
• 119323-52-3 (2R,3R)-2-Amino-3-tert-butoxy-butyric acid 

Downstream Products

• 1000778-59-5 C₄₈H₆₂N₁₄O₁₃ 
• 1000778-60-8 C₄₉H₆₄N₁₄O₁₂S 
• 1175537-23-1 human myelin basic protein fragment 87-99 

Relevant articles and documents

Fungal Dioxygenase AsqJ Is Promiscuous and Bimodal: Substrate-Directed Formation of Quinolones versus Quinazolinones

Previous studies showed that the FeII/α-ketoglutarate dependent dioxygenase AsqJ induces a skeletal rearrangement in viridicatin biosynthesis in Aspergillus nidulans, generating a quinolone scaffold from benzo[1,4]diazepine-2,5-dione substrates. We report that AsqJ catalyzes an additional, entirely different reaction, simply by a change in substituent in the benzodiazepinedione substrate. This new mechanism is established by substrate screening, application of functional probes, and computational analysis. AsqJ excises H2CO from the heterocyclic ring structure of suitable benzo[1,4]diazepine-2,5-dione substrates to generate quinazolinones. This novel AsqJ catalysis pathway is governed by a single substituent within the complex substrate. This unique substrate-directed reactivity of AsqJ enables the targeted biocatalytic generation of either quinolones or quinazolinones, two alkaloid frameworks of exceptional biomedical relevance.

Unwanted hydrolysis or α/β-peptide bond formation: How long should the rate-limiting coupling step take?

Nowadays, in Solid Phase Peptide Synthesis (SPPS), being either manual, automated, continuous flow or microwave-assisted, the reaction with various coupling reagents takes place via in situ active ester formation. In this study, the formation and stability of these key active esters were investigated with time-resolved 1H NMR by using the common PyBOP/DIEA and HOBt/DIC coupling reagents for both α- and β-amino acids. Parallel to the amide bond formation, the hydrolysis of the α/β-active esters, a side reaction that is a considerable efficacy limiting factor, was studied. Based on the chemical nature/constitution of the active esters, three amino acid categories were determined: (i) the rapidly hydrolyzing ones (t 24 h) in solution. The current insight into the kinetics of this key hydrolysis side reaction serves as a guide to optimize the coupling conditions of α- and β-amino acids, thereby saving time and minimizing the amounts of reagents and amino acids to be used-all key factors of more environmentally friendly chemistry.

Improved synthesis of d-allothreonine derivatives from l-threonine

The improved synthesis of protected d-allothreonine derivatives [Fmoc-d-alloThr(tBu)-OH (1) and Fmoc-d-alloThr-OtBu (2)] is described. The epimerization of cheap l-threonine (l-Thr) (3) with catalytic salicylaldehyde afforded a mixture of l-Thr (3) and d-alloThr (4) and separation of ammonium salt gave d-alloThr (4) in 96% de. The chemoselective deprotection of tert-butyl ether or tert-butyl ester of Fmoc-d-alloThr(tBu)-O tBu (5) easily succeeded in converting Fmoc-d-alloThr( tBu)-OH (1) or Fmoc-d-alloThr-OtBu (2), respectively.