4-naphthoquinone undergoes photochemical 2+2 addition at its 2- and 3-positions to alkenes. An elimination of hydrogen chloride from the adducts provides a facile and general synthetic method of 1,2-dihydrocyclobuta[b]naphthalene-3,8-diones.
                                    2-Chloro-1,4-naphthoquinone 在其 2-和 3-位与烯烃发生光
化学 2+2 加成。从加合物中消除
氯化氢提供了一种简便且通用的 1,2-二氢环丁 [b] 
萘-3,8-二酮合成方法。