Synthesis of p-phenylthio- peri-hydroxy polyaromatic compounds by strong-base-induced [4+2] cycloaddition of 4-(phenylthio)homophthalic anhydrides with phenylsulfinyl- dienophiles

Abstract

A direct and regioselective synthesis of p-phenylthio-substituted peri-hydroxy polyaromatic compounds (9-12) was developed via the strong-base-induced [4+2] cycloaddition of the 4-(phenylthio)homophthalic anhydrides (1a-d) to the phenylsulfinyl-substituted dienophiles (5-8). The sulfinyl group in 5-8 is the key to producing the desired reaction under mild conditions (at -20 °C to room temperature) in good yields. A reaction mechanism explaining the remarkable effect of the sulfinyl group is discussed.

Recent developments in the retro-Diels–Alder reaction

“…The treatment of adducts having sulfinyl substituted dienophiles (134) with NaH, resulted in the oxy-anion assisted rDA reaction and loss of CO 2 giving the cycloadduct 138. 51 As an alternate to thermally induced rDA reactions, many surface based catalysts have also shown activity for the rDA reaction (Fig. 2).…”