Application of the Mitsunobu-Type Condensation Reaction to the Synthesis of Phosphonate Derivatives of Cyclohexenyl and Cyclohexanyl Nucleosides
摘要:
1,4-trans-cyclohexanediol has been used as starting material for the synthesis of cyclohexenyl and cyclohexanyl nucleosides functionalized with a OCH2P(O)(OH)(2) moiety in a 1,4-cis relationship with the heterocyclic base. The methodology used is based on the Mitsunobu-type condensation of a conveniently functionalized alcohol with both purines and pyrimidines bases. In all cases (except for cytosine) the natural substituted derivative (N-9 for purines and N-1 for pyrimidines) were obtained as the major isomers. The N-1 cytosine derivative was thus obtained from its uracil analogue. Yields were higher when an allylic alcohol was used in the condensation. Far this reason, cyclohexanyl nucleosides were obtained from their cyclohexenyl analogues by reduction of the 2',3'-double bond. The phosphonomethoxy moiety was introduced prior to the coupling with the heterocyclic base to avoid protection or undesired alkylations of the bases during the derivatization of the 4'-alcohol function.
Synthesis of<i>syn</i>and<i>anti</i>1,4-Diols by Copper-Catalyzed Boration of Allylic Epoxides
作者:Mariola Tortosa
DOI:10.1002/anie.201100613
日期:2011.4.18
Two sides of the same coin: Syn and anti 1,4‐diols have been synthesized through the regio‐ and diastereoselective CuI‐catalyzed boration of allylicepoxides (see scheme; pin=pinacolato, TES=triethylsilyl). In situ protection of the alcohol allows isolation of syn and anti 1,4‐silyloxyboronates. Monoprotected 1,4‐diols can be prepared by a one‐pot addition–protection–oxidation sequence.
A general method for alkali-metal-promoted reductive difunctionalization of alkenes has been developed by means of reduction-resistant alkoxy-substituted electrophiles. A series of 1,2-diboration and 1,2-dicarbofunctionalization products can be synthesized by employing trimethoxyborane and strained cyclic ethers such as oxirane and oxetane. In addition, unsymmetrical carbo- or thioborations have been
A compound of formula (I) or a compound of formula (II) or pharmaceutically acceptable salts thereof, wherein R1-R7 and X are as defined in the description, and the use of these compounds in therapy, in particular in treating cancer or as an inhibitor of the interaction of the MDM2 protein with p53.
Ester der β-Carbolin-3-carbonsäure mit alizyklischen Alkoholen Synthese und Affinität zu Benzodiazepinrezeptoren
作者:Klaus H. Geldsetzer、Walter Schunack
DOI:10.1002/ardp.19903230104
日期:——
Es wurden Ester der β‐Carbolin‐3‐carbonsäure mit alizyklischen Alkoholen dargestellt und deren Affinität zum Benzodiazepinrezeptor in Mäusehirn‐Membranen bestimmt. Dabei wiesen die Substanzen 3d,f und 4b auffallend hohe Affinitäten (<70 nmol) auf. Für 3f läßt sich dies auf den Benzodiazepin‐Anteil im Molekül zurückführen. 4b verhält sich im GABA‐Shift wie Invers‐Agonisten des Benzodiazepinrezeptors
Expanding the Scope of Biomass-Derived Chemicals through Tandem Reactions Based on Oxorhenium-Catalyzed Deoxydehydration
作者:Mika Shiramizu、F. Dean Toste
DOI:10.1002/anie.201307564
日期:2013.12.2
New modes of DODH: Oxorhenium compounds act as deoxydehydration(DODH)/acid dual‐purpose catalysts to transform biomass‐deriveddiol substrates into a variety of commodity chemical precursors. The power of this approach is highlighted by a tandem [1,3]‐OH shift/DODH of 2‐ene‐1,4‐diols and 2,4‐diene‐1,6‐diols, and by a DODH/esterification sequence of sugar acids to unsaturated esters for the production