- Cyclobutane-derived diamines: Synthesis and molecular structure
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Cyclobutane diamines (i.e., cis- and trans-1,3-diaminocyclobutane, 6-amino-3-azaspiro[3.3]heptane, and 3,6-diaminospiro[3.3]heptane) are considered as promising sterically constrained diamine building blocks for drug discovery. An approach to the syntheses of their Boc-monoprotected derivatives has been developed aimed at the preparation of multigram amounts of the compounds. These novel synthetic schemes exploit classical malonate alkylation chemistry for the construction of cyclobutane rings. The conformational preferences of the cyclobutane diamine derivatives have been evaluated by X-ray diffraction and compared with the literature data on sterically constrained diamines, which are among the constituents of commercially available drugs.
- Radchenko, Dmytro S.,Pavlenko, Sergiy O.,Grygorenko, Oleksandr O.,Volochnyuk, Dmitriy M.,Shishkina, Svitlana V.,Shishkin, Oleg V.,Komarov, Igor V.
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experimental part
p. 5941 - 5952
(2010/11/04)
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- Synthesis of conformationally constrained diaminodicarboxylic acid derivatives
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(Chemical Presented) Functionally protected forms of three conformationally constrained diaminodicarboxylic acids were synthesized and characterized. 2,2′-Diaminospiro[3.3]heptane-2,2′-dicarboxylic acid, an analogue of diaminopimelic acid, was prepared in
- Weatherhead, Robin A.,Carducci, Michael D.,Mash, Eugene A.
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experimental part
p. 8773 - 8778
(2010/03/02)
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- Enantiopure spiro[3.3]heptane-2,6-dicarboxylic acid
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Using chiral HPLC and 13C NMR analyses, the optical purity of (+)-spiro[3.3]heptane-2,6-dicarboxylic acid (1) obtained by the known diastereomer method with brucine was first clarified to be 90% e.e., which was conventionally considered to be 100% e.e. Among the ester derivatives synthesized, dicinnamyl spiro[3.3]heptane-2,6-dicarboxylate (2) was found to show high optical separation ability on the chiral HPLC with cellulose phenyl carbamate stationary phase eluting with hexane/2-propanol (10/1, v/v) at a flow rate of 0.4 ml/min at 35 °C (separation factor, α, 1.14), and the isolated optically pure (+)- and (-)-2 show [α]D26 of +1.84° (c = 1.74, CHCl3) and -1.84° (c = 1.74, CHCl3), respectively. Acidic hydrolysis of optically pure (+)-/(-)-2 without racemization yielded optically pure (+)-/(-)-1, exhibiting [φ]40527 = +21.1° ([φ]D27 = +9.1°) (c = 5.33, acetone) and [φ]40527 = -21.1° ([φ]D27 = -9.1°) (c = 5.32, acetone), respectively.
- Tang, Hong-Zhi,Miura, Hiroshi,Kawakami, Yusuke
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- (±)-N9-(2-(hydroxymethyl)spiro[3.3]hept-6-yl)adenine. The first biologically active saturated analogue of adenallene with axial dissymmetry
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Synthesis of the title analogue 2 is described. Fecht's acid (3) was esterified with N,N-dimethylformamide dimethyl acetal to give monoester 4 along with diester 5. Compound 4 was transformed to ester amide 6 by the reaction with isobutyl chloroformate and triethylamine followed by ammonolysis. Hoffman rearrangement of 6 effected by lead tetraacetate in tert-butyl alcohol led to the N-tert-butoxycarbonyl ester 7. The latter was reduced with Ca(BH4)2 to give the protected amino alcohol 8. Removal of the N-tert-butoxycarbonyl group with 2 M HCl in methanol afforded the hydrochloride of amino alcohol 2. Reaction of 9 with 5-amino-4,6-dichloropyrimidine and triethylamine gave the pyrimidine derivative 10 which, in turn, was cyclized to 6-chloropurine 11a. Ammonolysis of the latter intermediate afforded the title analogue 2. The 1H NMR spectrnm of Fecht's acid (3) in CD3COCD3 showed that four methylene protons were magnetically nonequivalent (two quartets) whereas the other four were equivalent, forming a single doublet. Compound 2 inhibited the replication of human cytomegalovirus (IC50 32 μM) and growth of murine leukemia L1210 cells (IC50 30 μM). Zone assays showed inhibition of the following tumor cultures at 0.5 mg/disk: murine leukemia P388, mouse tumors PO3, C38, and M17/Adr as well as human tumors MCF-7 and CX-1.
- Jones,Drach,Corbett,Kessel,Zemlicka
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p. 6277 - 6280
(2007/10/03)
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