An Improved Method for the Preparation of Aromatic Diazoketones

The reactions of diazo compounds with lactones. Part 1. Cyclopropanespiro-β-lactones from diketene: synthesis and reactions

“…Thermal reactions were also carried out at higher temperatures by heating 3b and 4b in sealed glass tubes at 180 ЊC. Analysis ( 1 H-NMR) of the crude product showed that although reactions occurred (see below), the furanones 6b-8b (18), 4a (37) 3a (5), 4a (31) 3b (12), 4b (21) 4c (32) 3d (18), 4d (26) 3e (13), 4e (17) 3f (10), 4f (32) 12a (84) 12a (85) 12b (15-60) b 12c (31) 12e (26) 12f (14) 9a (2), 10a (6) 5a (22), 6a (5), 8a (1), 9a a Used as supplied (Aldrich). b The yield is reduced significantly on chromatography.…”

Reactions of ketenes. XX. Phenylketene dimethylacetal as synthon for the introduction of functionalized phenylethyl units

“…The Cu(acac), catalysed reaction between acetall and diazoacetophenone (5b) [34] was carried out as above reported for dihydrofuran 6a. After evaporation of the solvent under reduced pressure, the residue was distilled to give first the unchanged acetal 1 and further pure dihydrofuran 6b at bp 140-142°10.6 mm in 70% yields.…”

Marquage de la Pregnenolone au Carbjne 14 et au Deuterium en Position 21

“…Le double inconv6nient cit6 ci-dessus peut stre &it6 par addition de trigthylamine au milieu r6actionnel (12); ceci se v6rifie si on utilise des chlorures d'acides aromatiques. Dans notre cas, l'addition de trigthylamine s'est r6-v616e inopgrante, ce qui est g6nGralement le cas pour les chlorures d'acides aliphatiques poss6dant m atome d'hydrogene en CI (13).…”