- Syntheses of 2-Carbomethoxy-5,10-dimethyl-6,8-bisdehydroannulenone, a Potential Precursor of Macrocyclic Azulene Analogues, and (Z)- and (E)-14-Carbethoxy-2-carbomethoxy-5,10-dimethyl-6,8-bisdehydrofulvenes
-
The synthesis of 2-carbomethoxy-5,10-dimethyl-6,8-bisdehydroannulenone (15), a potential precursor of macrocyclic azulene analogues, and its elaboration into (E)- (19) and (Z)-14-carbethoxy-2-carbomethoxy-5,10-dimethyl-6,8-bisdehydrofulvene (20) is reported.The 1H NMR spectrum of 15 is interpreted to indicate that in the average conformation the C-12,13 double bond is not coplanar with the ring, and a reappraisal of the conformation of 2,5,10-trimethyl-6,8-bisdehydroannulenone (16b) is made.The fulvenes 19 and 20 show little or no paratropicity and serve as model systems for the estimation of paratropicity in 15 and related systems.
- Sharma, Vijay K.,Shahriari-Zavareh, Hooshang,Garratt, Peter J.,Sondheimer, Franz
-
-
Read Online
- Synthesis of 6- or 7- hydroxy and 6- or 7- methoxy tropanes
-
A novel Mannich type condensation between the monomethyl ester of acetonedicarboxylic acid, methylamine hydrochloride, and hydrolyzed dimethoxydihydrofuran gave 6- or 7- functionalized β-keto ester tropanes 12 - 15. Further elaboration afforded a series of 6- or 7- hydroxy and 6- or 7-methoxy 2β-methoxycarbonyl-3-aryltropanes.
- Chen, Zhengming,Meltzer, Peter C.
-
-
Read Online
- Synthesis of 3-[(tert-Butyldimethylsilyl)oxy]glutaric anhydride from citric acid
-
A new synthesis of 3-[(tert-butyldimethylsilyl)oxy]glutaric anhydride has been developed from citric acid, which is a commodity chemical and more than a million tons are produced every year by fermentation. The new synthetic approach demonstrated an efficient utilization of bioresource for the synthesis of intermediate of rosuvastatin.
- Jiang,Wang
-
-
Read Online
- Substituted azabicyclo octane compound, and intermediate and preparation method thereof
-
The invention relates to an intermediate of a substituted azabicyclo [3.2. 1] octane compound and a preparation method thereof. Specifically, the invention discloses an intermediate compound shown asa formula (I), a preparation method thereof and a method for preparing an azabicyclo [3.2.1] octane compound from the intermediate compound, wherein the definition of each group in the formula is shown in the specification and claims in detail.
- -
-
Paragraph 0406-0408
(2021/03/13)
-
- Chiral Aryliodine-Mediated Enantioselective Organocatalytic Spirocyclization: Synthesis of Spirofurooxindoles via Cascade Oxidative C-O and C-C Bond Formation
-
An enantioselective organocatalytic oxidative spirocyclization of alkyl 3-oxopentanedioate monoamide derivatives leading to the formation of diverse spirofurooxindoles with high enantioselectivity has been realized via chiral aryliodine-mediated cascade C-O and C-C bond formations. The reaction is postulated to proceed via oxidative C-O bond formation followed by oxidative C-C bond formation, with the latter being the enantioselectivity-determining step.
- Cao, Yang,Zhang, Xiang,Lin, Guangyu,Zhang-Negrerie, Daisy,Du, Yunfei
-
supporting information
p. 5580 - 5583
(2016/11/17)
-
- Ru-catalyzed asymmetric hydrogenation of 3-oxoglutaric acid derivatives via solvent-assisted pinpoint recognition of carbonyls in close chemical propinquity
-
Upon comparison of hydrogenation rates of various β-ketocarboxylic acid derivatives, β-ketoamides were found to be hydrogenated slightly faster than β-ketoesters in EtOH in the presence of [RuCl(benzene)(S)- SunPhos]Cl at 70 °C with 20 bar of hydrogen. In THF these differences were so sharpened that β-ketoamides were hydrogenated even faster than in EtOH while the esters were extremely slow. Based on these findings, a series of 3-oxoglutaric acid derived with ester and amide moieties on the two ends were hydrogenated to 3-hydroxyl products with high enantioselectivities.
- Li, Wanfang,Ma, Xin,Fan, Weizheng,Tao, Xiaoming,Li, Xiaoming,Xie, Xiaomin,Zhang, Zhaoguo
-
supporting information; experimental part
p. 3876 - 3879
(2011/10/01)
-
- An efficient process for the manufacture of carmegliptin
-
A short and high-yielding synthesis of carmegliptin (1) suitable for large-scale production is reported. The tricyclic core was assembled efficiently by a decarboxylative Mannich addition-Mannich cyclization sequence. Subsequent crystallization-induced dynamic resolution of enamine 7 using (S,S)-dibenzoyltartaric acid was followed by diastereoselective enamine reduction to give the fully functionalized tricyclic core with its three stereogenic centers. The C-3 nitrogen was introduced by Hofmann rearrangement of amide 28, and the resulting amine 10 was coupled with (S)-fluoromethyl lactone 31. Following cyclization to lactam 13 and amine deprotection, 1 was obtained in 27-31% overall yield with six isolated intermediates.
- Abrecht, Stefan,Adam, Jean-Michel,Bromberger, Ulrike,Diodone, Ralph,Fettes, Alec,Fischer, Rolf,Goeckel, Volker,Hildbrand, Stefan,Moine, Gerard,Weber, Martin
-
experimental part
p. 503 - 514
(2012/01/03)
-
- Tropane analogs and methods for inhibition of monoamine transport
-
New tropane analogs that bind to monoamine transporters are described, particularly, 8-aza, 8carbo and 8-oxo tropanes having 6- or 7-substituents. The compounds of the present invention can be racemic, pure R-enantiomers, or pure S-enantiomers. Certain preferred compounds of the present invention have a high selectivity for the DAT versus the SERT. Also described are pharmaceutical therapeutic compositions comprising the compounds formulated in a pharmaceutically acceptable carrier and a method for inhibiting 5-hydroxy-tryptamine reuptake of a monoamine transporter by contacting the monoamine transporter with a 5-hydroxytryptamine reuptake inhibiting amount of a compound of the present invention. Preferred monoamine transporters for the practice of the present invention include the dopamine transporter, the serotonin transporter and the norepinephrine transporter.
- -
-
Page column 23
(2008/06/13)
-
- Synthesis of 6- and 7- hydroxy-8-azabicyclo[3.2.1]octanes and their binding affinity for the dopamine and serotonin transporters
-
Cocaine is a potent stimulant of the central nervous system. Its reinforcing and stimulant effects are related to its ability to inhibit the membrane bound dopamine transporter (DAT). Inhibition of the DAT causes an increase of dopamine in the synapse with a resultant activation of postsynaptic receptors. The rapid onset and short duration of action of cocaine contribute to its high addictive potential. Consequently, the design of tropane analogues of cocaine that display longer onset times on the DAT and extended duration of action is driven by the need to develop cocaine medication. This study extends the exploration of bridge hydroxylated azabicyclo[3.2.1] octanes (tropanes). A series of 6- and 7-hydroxylated tropanes was prepared and evaluated biologically. Structure activity relationships lead to the following conclusions. Bridge hydroxylated tropanes retain biological enantioselectivity but display higher DAT versus SERT selectivity, particularly for the 3α-aryl compounds as compared with the 3β-aryl compounds, than the bridge unsubstituted analogues. The 7-hydroxyl compounds are more potent at the DAT than their 6-hydroxyl counterparts. The general SAR of the tropanes is maintained and the rank order of potencies based on substitution at the C3 position remains 3,4-dichloro > 2-naphthyl > 4-fluoro > phenyl.
- Meltzer,Wang,Chen,Blundell,Jayaraman,Gonzalez,George,Madras
-
p. 2619 - 2635
(2007/10/03)
-
- PREPARATION OF ENOL LACTONES OF 3,5,7-TRIKETO AND 3,5,7,9-TETRAKETO ACIDS BY THE CONDENSATION OF 4,6-DIMETHOXY-2-PYRONE WITH ANIONS OF MONO- AND DIKETONES
-
Condensations of the anions of acetone, acetophenone, acetylacetone and benzoylacetone with 4,6-dimethoxy-2-pyrone afforded good yields of the corresponding 6 substituted 4-methoxy-2-pyrones which were converted to the 4-hydroxy analogs by demethylation with iodotrimethylsilane.
- Ray, John A.,Harris, Thomas M.
-
p. 1971 - 1974
(2007/10/02)
-