Reactions of 2-Hydroxytryptophol: Results of Strong Acid and Alkaline Treatments of 2-Hydroxytryptophol
Upon being warmed at 90 deg C in trifluoromethanesulfonic acid for 42-78 h, 2-hydroxytriptophol (4a) gave 3-ethylideneoxidoles (E- and Z-form) (5a), while 3-methyl- (4b) or 3-ethyl-2-hydroxytryptophol (4c) gave the corresponding 3-alkylideneoxindoles (5b,