Sorokinianin: A novel phytotoxin produced by the phytopathogenic fungus Bipolaris sorokiniana

Formal Enantioselective [4+3] Cycloaddition by a Tandem Diels–Alder Reaction/Ring Expansion

“…The reaction was allowed to warm to 0 8C over 2 h. After stirring at 0 8C for 30 min, the reaction was poured into 50 mL ice/water. The mixture was extracted with ether (2 ), and the combined extracts were washed with water and brine, dried over Na 2 SO 4 , and concentrated. The resulting yellow solid was chromatographed on silica to give (S)-3,3'-di(2-hydroxyphenyl)-2,2'-dihydroxy-1,1'-binaphthyl as white crystalline solid; yield: 375 mg (60 %).…”

“…The bicycloA C H T U N G T R E N N U N G [3.2.1]octane moiety is the basic framework of numerous natural products [1][2][3] and has been widely used as a strategic building block in natural product synthesis. [4] Appropriate modification of the bicyclic framework can lead to products containing multiple stereocenters.…”

“…(2)], [7] and the tandem cyclopropanation/Cope rearrangement between vinylcarbenoids and dienes [Eq. (3)].…”

Phytotoxins and Plant Pathogenesis

“…At these concentrations, prehelminthosporol produces necrosis in barley leaves (Nilsson et aI., 1993). At a concentration of 300 11M, sorokinianin inhibits germination of barley seeds by 50% and kills all protoplasts from barley leaves (Nakajima et aL, 1994). The toxin also increases leakage of A TP from intact roots ofbarJey seedlings grown in nutrient solution (Liljeroth et aI., 1994).…”

Enantioselective Synthesis of Bioactive Molecules Related to Plant Protection and Physiology.

“…Availability of the compound, however, was limited and the absolute configuration was unknown (ref. 30). We noticed its biological activity and decided to synthesize the enantiomer to elucidate the absolute configuration as well as to obtain substantial amount of the material .…”