Diaryl heptanoids

Hanaoka, and U. Sankawa. Inhibition of prostaglandin and leukotriene biosynthesis by gingerols and diaryl-heptanoids. Chem Pharm Bull 1992 40(2) 387-391. 

In the family of Betulaceae open chain diaryl-heptanoids were found in Alnus and Betula species. 

If the actual biosynthesis of the 9-phenylphenalenones is related to the scheme proposed by Thomas, then the cyclization of the diaryl-heptanoid intermediate [e.g. (73)] could proceed through the biosynthetic equivalent of a Diels-Alder reaction. As was mentioned on page 181, the diaryIheptadienone (65) has been synthesized and converted into lachnanthocarpone through the diarylheptanoid orthoquinone (66) in vitro (52). To the extent that this result shows that a 9-phenyl-phenalenone can be constructed from a suitable diarylheptanoid, it can be considered as adding support to Thomas hypothesis. 

Fourteen new macrocyclic diaryl ether heptanoids have been described (Table 4). The total syntheses of compounds 88, 89, 90, 91, 94 and 101 have also been reported (cf. Table 4). Based on synthetic and spectroscopic evidence, the structure of garuganin III has been revised to 101 [46]. 

Type I non-phenolic linear diarylheptanoids Type II phenolic linear diarylheptanoids Type III macrocyclic biarylheptanoids Type IV macrocyclic diaryl ether heptanoids Type V diarylheptanoids with cyclised C7-chain. 

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