Aromatische Spirane, 20. Mitt.: Darstellung von dimethylsubstituierten 2-Carboxymethyl-indan-1-onen und Benzylchloriden als Synthone f�r Synthesen von di- bis tetramethylierten 2,2?-Spirobiindandionen
摘要:
The isomeric dimethyl methylbenzoates 5, obtained from the bromides via Grignard reactions with dimethylcarbonate, were reduced with LiAlH4 to the hydroxymethyl derivatives 6. The latter were then transformed both to the benzylchlorides 7 (with SOCl2) and to the aldehydes 8 (with pyridinium chlorochromate). Knoevenagel-Doebner reaction of 8 afforded the acrylic acids 9 which (after hydrogenation to 11) were cyclized to the desired indanones 12 with polyphosphoric acid. On the other hand, 12c and 12e were prepared from dimethyl 3-chloropropiophenone (14) by warming with sulfuric acid. After NaH-catalyzed reaction with dimethylcarbonate, the indanones 12 gave the ketoesters 15 which then could be hydrogenated to the indanes 16. All reactions proceeded with satisfactory to excellent yields (60-90%).
Radical-Cation Vinylcyclopropane Rearrangements by TiO<sub>2</sub> Photocatalysis
作者:Naoya Maeta、Hidehiro Kamiya、Yohei Okada
DOI:10.1021/acs.joc.0c00544
日期:2020.5.15
Radicalcation vinylcyclopropane rearrangements by TiO2 photocatalysis in lithium perchlorate/nitromethane solution are described. The reactions are triggered by oxidative single electron transfer, which is followed by immediate ring-opening of the cyclopropanes to generate distonic radicalcations as unique reactive intermediates. This approach can also be applied to vinylcyclobutane, leading to the
Neue Synthesen von 2-Amino-5,6-dihydro-4H-1,3-thiazinen
作者:H. W. Schubert、O. Behner
DOI:10.1002/ardp.19683011006
日期:——
Es wird die Darstellung von 2‐Amino‐dihydrothiazinen 4 durch Behandlung von 2‐tert.‐Butylamino‐dihydrothiazinen 6, N‐γ‐Hydroxypropyl‐N′‐tert.‐butyl‐thioharnstoffen 11 oder 2‐Acylamino‐dihydrothiazinen 14 mit Säuren beschrieben.
Synthesis of Trifluoromethylthiolated Alkenes and Ketones by Decarboxylative Functionalization of Cinnamic Acids
作者:Shen Pan、Yangen Huang、Feng-Ling Qing
DOI:10.1002/asia.201601098
日期:2016.10.20
A tunable decarboxylative trifluoromethylthiolation of cinnamic acids with AgSCF3 was developed to afford trifluoromethylthiolated alkenes or ketones by using transition metal‐mediated conditions.