Divergent Behavior of β‐Carbonyl‐Substituted 1<i>H</i>‐Benzo[<i>f</i>]chromenes Under Henry Reaction Conditions

Abstract A series of β‐carbonyl‐substituted 1 H ‐benzo[ f ]chromenes has been introduced into the reaction with nitromethane in the presence of ammonium acetate. It has been shown that in the case of 1 H ‐benzo[ f ]chromene‐2‐carbaldehydes, the reaction does not stop at the formation of the classical Henry reaction products − β‐nitroalcohols, but their dehydration to nitrovinylchromenes takes place. In the case of alkyl(benzochromen‐2‐yl)ketones, 3‐alkyl‐2‐(2‐nitrovinyl)‐1 H ‐benzo[ f ]chromenes are formed, and methoxalyl‐substituted benzochromenes give 10‐amino‐7a,8‐dihydrobenzo[5,6]chromeno[2,3‐ b ]pyrrol‐9(11 H )‐ones under the Henry reaction conditions.