Df. Schneider et Ms. Viljoen, SYNTHESIS OF ANNULATED 4-ALKYLIDENEBUTENOLIDES FROM NATURAL OCCURRINGDIOSPHENOLS, Synthetic communications, 27(19), 1997, pp. 3349-3360
Diosphenol(3) and Psi-diosphenol (4), two constituents of the essentia
l oil from the buchu plant, Borosma betulina (Bartl.), were utilized f
or the synthesis of the anulated 4-ylidenebutenolides (5) and (6).