Ingenanes

Scheme 8.48 Construction of the ingenane ABCD ring system.

Gotta H, Adolf W, Opferkuch HJ, Hecker E. (1984) On the active principles of the Enphorbiaceae, IX. Ingenane type diterpene esters from five Euphorbia species. Z Naturforsch B 39 683-694 Hohmann J, Evanics E, Berta L, Bartok T. (2000) Diterpenoids from Euphorbia peplus. Planta Med 66 291-294 Ivanova A, Khozin-Goldberg 1, Kamenarska Z, Nechev J, Cohen Z, Popov S, Stefanov K. (2003) Lipophylic componnds from Euphorbia peplis L. — a halophytic plant from the Bnlgarian black sea coast. Z. Naturforsch 58c 783-788. 

Several studies have examined the chemistry of Euphorbia species. A majority of these investigations have focused on the chemical character of the plant latex relative to taxonomy (, ) or mammalian toxicity Toxic Ingenane diterpenes (phorbols) have also been... 

A synthetic application is demonstrated by Tanino and his co-workers who reported a total synthesis of ingenol 14 using this methodology.Use of methylaluminum bis(2,6-dimethyl-4-nitrophenoxide) promoted both cyclization and following rearrangement reactions smoothly to construct an ingenane skeleton 15 (Scheme 2). 

Ingenanes (C5 G7 ] C7 ] G3) include irritants and secondary tumour promoters (cocarcinogens) from Euphorbia species (Euphorbiaceae) that activate PKC. While the non-ester... 

A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed to detect tumor-promoting diterpene esters of the tigliane and ingenane types within plant extracts. Fractionation on a Cig HPLC column was followed by MS-MS-multiple reaction monitoring (MRM). 

In the laboratory of J.H. Rigby, synthetic studies were undertaken on the ingenane diterpenes. During these studies, it was necessary to investigate the ring opening reactions of a structurally complex allylic epoxide intermediate. This allylic epoxide was prepared from a 1,3-diene in three steps dihydroxylation, epoxidation and Corey-Winter olefination. 

Rigby, J. H., Bazin, B., Meyer, J. H., Mohammadi, E. Synthetic Studies on the Ingenane Diterpenes. An Improved Entry into a trans-Intrabridgehead System. Org. Lett. 2002,4, 799-801. 

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