Lolium cuneatum

An intermediate 5-hydroxy-5,6-dihydro-2/7-pyrrolo[l,2- ][l,2]oxazin-7(4a//)-one 142 has been described in the total synthesis of (—)-loline, a pyrrolizidine alkaloid extracted from rye grass Lolium cuneatum. The key step of the synthesis was an intramolecular cycloaddition of acylnitrosodienes (obtained by in situ oxidation of the corresponding hydroxamic acids 143). This reaction generated predominantly the rro/o-stereoisomer that was further cleaved at the N-O bond with Na(Hg) and further elaborated in several steps to reach the target compound (Scheme 19) <2001J(P 1)1831 >. 

The simple necine bases loline (18), norloline (19), and lolinine (20) have been identified previously from Lolium cuneatum Nevski.7 Further investigations on the seeds of this plant by Russian workers have established the presence of four new alkaloids. N-Formylnorloline (21),8 JV-methyl-loline (22), JV-acetylnorloline (23), and AT-formyl-loline (24)9 have been identified. In addition, a novel dimeric pyrrolizidine alkaloid, lolidine, containing chlorine, was isolated in trace amounts (7 mg from 10 kg of seeds). The structure (25) has been suggested for lolidine on the basis of spectral data.10... 

The structure (25) has been deduced for both loline, an alkaloid of Lolium cuneatum Nevski, ° and festucine, a constituent of Festuca arundinacea Schreb. The identity of loline and festucine has now been confirmed by direct comparison. 

Lolium cuneatum Nevski Loline, lolinine, norloline. (311)... 

Batirov, E. Kh., V. Malikov, and S. Yu. Yunusov Lolidine, a New Chlorine Containing Alkaloid from Lolium cuneatum Seeds. Khim. Prir. Soedin. 1976,63 [Chem. Abstr. 85, 74883 (1976)]. 

Alkaloids from Lolium cuneatum Seeds. Khim. Prir. Soedin. 1976,120 [Chem. 

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