Homodaphniphyllate, methyl

The carbon skeletons of the Daphniphyllum alkaloids consist of thirty or twenty-two carbon atoms. Probably the C22 alkaloids are formed by oxidative cleavage of eight carbon atoms from the C30 compounds. Methyl homodaphniphyllate [23, m/e 359(M+), 286, and 272], one of the representative C22 alkaloids, was isolated from the fruits of D. macropodum (19) but not from the bark and leaves of the same plant. The structure of this alkaloid (23) was deduced by chemical transformation from daphniphylline (1) which had already been carried out in several steps. Oxidation of deacetyldaphniphylline (2) with NaI04 followed by reduction with NBH afforded daphnialcohol [24, mp 239-241.5° (as hydrochloride) C21H350N], which was further converted via the corresponding tosylate (25, mp 107.5°) and nitrile (26, mp 156°) to homodaphniphyllic acid (27), which was directly treated with 20% methanolic HC1 to afford methyl homodaphniphyllate (23). This alkaloid was also obtained in 20% yield by Beckmann... 

Biogenetically, methyl homodaphniphyllate (23) must be produced from codaphniphylline (9), which belongs to a group of the C30 alkaloids, by oxidative removal of the oxygen heterocyclic moiety. 

Further reports on the chemistry of daphniphylline (1), methyl homodaphniphyl-late (90), and daphnilactone-B, isolated from Daphniphyllum teijsmanni Zollinger, D. macropodum Miquel, and D. humile Maxim, have appeared. ... 

Methyl Homodaphniphyllate.—Daphniphylline has been converted into methyl homodaphniphyllate (90). Treatment of daphnialcohol (96) with toluene-p-sulphonyl chloride in pyridine gave the tosylate (97). Treatment of (97) with ethanolic potassium cyanide afforded a mixture of the nitrile (98) and the amide (99). This mixture was hydrolyzed with aqueous HCl, and the resulting acid was esterified with methanolic HCl to afford (90). The authors proposed that methyl... 

This alkaloid contains the 2-azabicyclo[3,3,l]nonane ring system characteristic of all the Daphniphyllum alkaloids. It represents a new structural type, having four rings with the C-8 atom common in a spiro-system. Its skeleton may be related to methyl homodaphniphyllate (59) by insertion of a single carbon unit (C-26) and lactonization. 

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