2-(1-Hydroxyalkyl)-1, 4-naphthoquinones are found to react with pyrrolidino enamines in toluene to give 1H-naphtho [2, 3-c] pyran-5, 10-diones in good yields via a tandem conjugate addition–cyclization sequence, followed by an elimination of pyrrolidine. 2- Hydroxymethyl-1, 4-naphthoquinone and morpholino enamines undergo a similar sequence, without loss of morpholine, to yield 3-morpholino-3, 4-dihydro-1H-naphtho [2, 3 ...
