Synthesis of Substituted 3-Iodocoumarins and 3-Iodobutenolides via Electrophilic Iodocyclization of Ethoxyalkyne Diols
作者:Maddi Sridhar Reddy、Nuligonda Thirupathi、Madala Hari Babu、Surendra Puri
DOI:10.1021/jo400499r
日期:2013.6.21
A convenient and general synthesis of various 4-substituted 3-iodocoumarins and 4,5-disubstituted 3-iodobutenolides is described via an exclusive 6-endo-dig iodocyclization of 3-ethoxy-1-(2-alkoxyphenyl)-2-yn-1-ols and 5-endo-dig iodocyclization of 1-alkoxy-4-ethoxy-3-yn-1,2-diols, respectively. The reaction is carried out under very mild conditions using I2 in CH2Cl2 or toluene at room temperature
Synthesis of Novel 3-Allylbenzofurans via a Wittig Olefination and Claisen Rearrangement Sequence
作者:M. G. Kulkarni、Ravindra M. Rasne
DOI:10.1055/s-1997-1362
日期:1997.12
A short and novel synthesis of hitherto unknown 3-allylbenzofurans is described. Wittig olefination of protected 2-hydroxybenzaldehydes followed by Claisen rearrangement resulted in the formation of pent-4-en-als. These, on deprotection and dehydration, gave 3-allylbenzofurans.
An optically active proton-ionizable lariat crown ether derivative 2 was prepared. Host 2 displays enantiomeric selectivity toward phenylglycinol (Klarge/Ksmall=3.2) and phenylalaninol (Klarge/Ksmall=1.7). The key intermediate 1 was synthesized in two steps from commercially available binaphthol in 30% yield.
via photoinduced electron transfer from the N-nitrosoaminophenol moiety to the rosamine moiety. NO release from NO-Rosa was detected by ESR spin trapping and a NO fluorescent probe. Cellular NO release control was achieved in HEK293 cells using a NO fluorescent probe, DAF-FM DA. Furthermore, temporally controlled NO-induced vasodilation was demonstrated by treatment of a rat aortic strip with NO-Rosaex
Synthesis of 4-trifluoromethyl-2<i>H</i>-chromenes <i>via</i> the reaction of 2-(trifluoroacetyl)phenols with vinyltriphenylphosphonium chloride
作者:Alexander S. Golubev、Petr N. Ostapchuk、Tatiana V. Strelkova、Nikolai D. Kagramanov、Kyrill Yu. Suponitsky、Rina U. Takazova、Nikolai D. Chkanikov
DOI:10.1039/d2ob01177h
日期:——
Substituted on the benzene ring 4-CF3-2H-chromenes have been prepared from substituted 2-(trifluoroacetyl)phenols and vinyltriphenylphosphonium chloride according to the Schweizer protocol in moderate to excellent yields. The influence of the type and the position of aromatic ring substituents on yields of 4-CF3-2H-chromenes have been investigated. It has been shown that 4-CF3-2H-chromenes are convenient
根据 Schweizer 协议,在苯环上取代的 4-CF 3 -2 H -色烯由取代的 2-(三氟乙酰基)苯酚和乙烯基三苯基氯化鏻以中等至优异的产率制备。研究了芳环取代基的类型和位置对4-CF 3 -2 H-色烯收率的影响。已经表明4-CF 3 -2 H-色烯是4-CF 3 -香豆素的方便前体。