The alkaloids of two coccinellid beetles, Calvia14‐guttata and C.10‐guttata have been studied. The major alkaloid of these two species is the new piperidinic cis‐lactone 1a, for which the name calvine has been coined. The corresponding trans‐lactone 1b (2‐epicalvine) is also present as a minor constituent (±10%) in both species. We report here the structure determination and the total synthesis of these compounds. Kept in methanolic solution, these lactones undergo epimerisation as well as opening of the lactone ring leading to a complex mixture of nine main components.
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