Ibotenic acid synthesis

A similar reaction was used for the synthesis of muscazone from ibotenic acid (Eq 17).40 Only the 2 and 3 positions interchange. 

A review concerning the chemistry, biogenesis, and pharmacology of Amanita muscaria components includes a comprehensive coverage of the muscarine alkaloids. (+)-i -4-Hydroxypyrrolidin-2-one has been isolated from this source. A method for the identification of stereoisomeric muscarines by combination vacuum pyrolysis-g.c. analysis has been described. A micro method for the determination of ibotenic acid and other 3-hydroxyisoxazoles has been developed. Stereospecific syntheses for DL-muscarine and DL-a//o-muscarine have been reported. Pyrolysis of (1) yielded the carboxylic acid (2) and the bromolactone (3) which served as key compounds in the synthesis of the muscarines. The minor component (3) was shown to be an intermediate in the formation of (2) and therefore the conversion [(3)- -(2)] could be written as an intramolecular Sn2 displacement on an a-lactone (4). However, treatment of (3) with... 

Synthesis Goth, Helvetica Chimica Acta 50 137, 1967 Chilton, unpublished (light-catalyzed rearrangement of ibotenic acid)... 

Kishida, Y etal. 19 66. Studies on acetylenic compounds, xliii. Synthesis of ibotenic acid Chemical andPharmacolo calBulletin Japan 14 92-94. 

Synonyms L-firyr/ racetic acid dihydro-ibotenic acid Dihydroibotensaure Tricholomisaure Physical C,H,NjO molccularwt. 160.13 c 37.50% h 5.04% n 17.49% O 39.97% Isolation , Takemoto, Yakugaku Zasshi 84 1183, 1964 Tricholoma muscarium) Takeda Ltd., Japanese pat. 69 16,354, i9 9 [Incholomopsis ruulans) Synthesis Kamiya, Chemical and Pharmacolo cal Bulletin Japani. 1307,1966 ... 

The first synthesis of ibotenic acid was published as early as I%5 by Gagneux et al. 53). 3-Bromoisoxazole-5-carboxylic acid was used as the starting material and was transformed into the final product by the steps shown in Scheme 14. Later, a few other synthetic methods were reported 55,56). The procedure elaborated by Nakamura (57) (Scheme 15), the starting point being diethyl 3-chloroglutaconate, seems to be the most efficient. The intermediate ethyl 3-hydroxy-5-isoxazoleacetate was also used, via anhydrous Curtius rearrangement of its hydrazide, for the preparation of muscimol. 

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