A new modification of the pomeranz–fritsch isoquinoline synthesis

Synthesis of indeno[1,2,3-ij]isoquinolines

“…Et20/(CF3C0)20 (17) with a singular lack of success. The same was true when 11 was treated with 6 M HCI (18) or its tosyl derivative with 6 M HCI in dioxane (19). The reasons for the failure of this cyclization in this seemingly highly activated system are not apparent.…”

A New Modification of the Pomeranz-Fritsch Reaction

“…We have studied Pomeranz-Fritsch based reactions of a well known low reactive substrate (2). Careful tuning of concentrations and conditions allowed yield improvement from less than 15% to up to 60%.…”

Diastereoselective radical cyclization reactions: the synthesis of O-methylcorytenchirine

“…A solution of Bu 3 SnH (218 mg, 0.75 mmol) and AIBN (40 mg, 0.28 mmol) in degassed benzene (4 mL) was then added dropwise with a syringe pump over 6 h. The solution was then stirred at reflux for a further 4 h before it was cooled to room temperature and the solvent removed under reduced pressure. The residue was purified by radial preparative layer chromatography (60% ethyl acetate in light petroleum) to afford the cyclized product 23 as a solid (145 6.59, 6.63, 6.67, 6.76 (4s, 1H each, 4 x ArH); 13C NMR δ 21.91 (CH3), 34.95 (5-CH2), 38.86 55.79 and 55.86 (4 x OCH3),108.35,108.47,109.76,110.87 (1,4,9,122.15,124.76,124.95,129.99 (4a,8a,12a,147.42,147.82,147.94,148.58 (2,3,10,; m/z: 383(M+, 9%), 369(2), 368 (9), 206(2), 179 (12), 178(100), 163 (9), 135(5), 117(3), 115(2), 107(2), 105(3), 103(3), 91(7), 79(4), 77(4), 65 (2); Anal. Calcd.…”