Bisbenzocyclooctadiene lactones

Biaryl phenol coupling.1 The natural dibenzylbutanolide lignans, prestegane A (la) and B (lb), are converted to the corresponding bisbenzocyclooctadiene lactones (2) by oxidation with Ru02 in TFA-TFAA in 80-85% yield. The usual reagent for this oxidation, thallium tris(trifluoroacetate), is less efficient (45-50% yields). 

A. T. (1984) Neoisostegane, a new bisbenzocyclooctadiene hgnan lactone from Steganotaema araliacea J Nat Prod. 47, 600-605. 

Bisbenzocyclooctadienes. The nonph lignan lactones is accomplished with Rc 0-... 

Bisbenzocyclooctadienes The nonphenolic coupling used in the synthesis of lignan lactones is accomplished with Re207 in TFA-TFAA media. 

Hicks R P, Sneden A T 1983 Neoisostegane, a new bisbenzocyclooctadiene lignan lactone from Steganotaenia araliacea Hochst. Tetrahedron Lett 24 2987 - 2990... 

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See also in sourсe #XX -- [ ]

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