Paspalic acid

Preparing Lysergic Acid from Paspalic Acid Jean-Claude Gaullier... 

It is known that lysergic acid can be prepared by isomerizing paspalic acid, using potassium hydroxide Helvetica Chimica Acta, 64, 47, 478 (1981)) or sodium hydroxide Helvetica Chimica Acta, 47, 115, 1052 (1964) and JP70013302), but these processes do not allow either good yields or a product comprising small quantities of isolysergic acid to be obtained industrially. 

A process has now been found, which is the subject of the present application, allowing lysergic acid of sufficient purity to be obtained in very good yields by isomerizing paspalic acid. 

Oxidation of C(17) of 19 generates 6, and further oxidation steps lead to paspalic acid (22), the A -isomer of 1 (Scheme 5). In cell-free extracts, the microsomal (membrane) fraction contains oxygenases for conversion of 19 into 6, and... 

Hydroxypalisadin B, in P-10003 5)5-Hydroxypalisadin B, in P-10003 11-Hydroxypalmitic acid, see H-10160 10-Hydroxy-cw-paspalic acid amide, in P-10013... 

Fig. 4.5 Biosynthesis of ergoline alkaloids II. Paspalic acid as the key intermediate between clavine type and lysergic amide type ergoline alkaloids (oxidation of elymodavine by elymodavine 17-monooxygenase and isomerization of the resulting paspalic acid to activated lysergic acid)...

Figure 16 Conversion of elymoclavine to paspalic acid catalyzed by elymoclavine 17-mono-oxygenase...

The first simple derivative of lysergic acid, ergometrine, was isolated by three groups of researchers and thus it has two other alternative names—ergobasine and ergonovine. Later free lysergic acid, paspalic acid and many of their derivatives were found in the nature. All of them are summarised in the Table 4... 

Table 4 Simple derivatives of lysergic and paspalic acids...

Figure 9 Lysergic and paspalic acids and their simple derivatives...

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