57266-56-5Relevant academic research and scientific papers
Synthesis of a new 2,3-diaminoconduritol with conduritol F structure
Ekmekci, Zeynep,Balci, Metin
, p. 4988 - 4995 (2013/01/14)
A new 2,3-diaminoconduritol derivative with the conduritol F structure was prepared starting from cyclohexa-1,4-diene. Initially, a lactam, prepared by the cycloaddition of chlorosulfonyl isocyanate (CSI) to cyclohexa-1,4-diene, was converted into an amino acid. The conversion of the acid functionality into an isocyanate resulted in the formation of an imidazolidinone derivative, formed by an intramolecular cyclization. In the second part of this work, the known anhydride, 3a,4,7,7a-tetrahydroisobenzofuran-1,3-dione was successfully converted into the desired bis(carbamate). The bromination of the double bond in the six-membered ring followed by a DBU-induced (DBU = 1,8-diazabicyclo[5.4.0] undec-7-ene) HBr elimination furnished the symmetrical diene. The photooxygenation of the diene unit afforded the bicyclic endoperoxide. The reaction of the endoperoxide with thiourea followed by acetylation resulted in the formation of a syn-configured diacetate. The deprotection of the urethane and acetate groups gave the new 2,3-diaminoconduritol with the conduritol F structure. A new 2,3-diaminoconduritol with the conduritol F structure was prepared starting from the known anhydride 3a,4,7,7a-tetrahydroisobenzofuran-1, 3-dione, which was successfully converted into the desired diene with bis(carbamate) functional groups. The photooxygenation of the diene followed by cleavage of the peroxide linkage and removal of the protecting groups gave the new 2,3-diaminoconduritol. Copyright
The first direct enzymatic hydrolysis of alicyclic β-amino esters: A route to enantiopure cis and trans β-amino acids
Forro, Eniko,Fueloep, Ferenc
, p. 6397 - 6401 (2008/02/13)
The first direct enzymatic method is reported for the synthesis of cis and trans βamino acid enantiomers through the lipase-catalyzed enantioselective hydrolysis of alicyclic β esters in organic media. High enantioselectivities (E usually > 001) were observed when the Candida antarctica lipase B catalyzed reactions were performed with H2O (0.5 equivalents) in iP iPr2O at 5°C. The resolved products, obtained in good yields (≥42%), could be easily separated.
EXPERIMENTAL STUDIES OF THE ANOMERIC EFFECT. PART 2 RING INVERSION AND NITROGEN INVERSION EQUILIBRIA IN CIS-DECAHYDROQUINAZOLINES
Booth, Harold,Khedhair, Khedhair A.,Al-Shirayda, Hatif A. R. Y.
, p. 1465 - 1476 (2007/10/02)
The positions of conformational equilibria due to the double ring inversion in cis-decahydroquinazoline (7-->//07-->8 1.08 kcal mol-1; -ΔG09-->10 1.10 kcal mol-1) for the conformation which would allow the lone pairs on N(1) and N(3) to lie on the hindered 'inside' face of the molecules.However, the values of 3J(CHNH) coupling constants for both cis-decahydro-3-methylquinazoline (10) and cis (4aH, 8aH) cis (2H, 8aH)-decahydro-2,3-dimethylquinazoline (14) show that the N-inversion equilibrium at N(1) prefers the conformation in which N(1)-H is 'inside' (axial), and N(1)-lone pair equatorial, thus demonstrating the ability of the anomeric effect to outweigh steric repulsions.
