Enol lactones secophthalideisoquinolines

In Table VI secophthalideisoquinoline alkaloids and their precursors are presented. They form four series of seco bases from enol lactones to diketo adds ending with ene lactams, which in all probability are not true alkaloids but products arising during the extraction process. The classic precursors of... 

In this chapter the proposed (5) division of secophthalideisoquinolines into the four subgroups and the nomenclature have been preserved. Since the publication of the most recent review (5), information about the synthesis of the missing ( )-narceine enol lactone (102) (87), the isolation of ( )-fumaramine (112) from Fumaria vailanti (88), and the discovery of a new seco alkaloid, coryrutine (118), from Corydalis rutifolia (89) has appeared. In the former plant fumaramine (111) (55) and in the latter N-methylhydrasteine... 

The secophthalideisoquinoline enol lactones may exist as Z or geometric isomers. Three pairs of such isomers are known aobamidine (96) (Z) and adlumidiceine enol lactone (97) ( ), /V-methylhydrastine (98) (Z) and (E)-N-methylhydrastine (99) ( ), (Z)-narceine enol lactone (101) and ( )-narceine enol lactone (102). Three of these enol lactones (99, 101, 102) are synthetic products. Lists of these alkaloids, the plant species in which they occur, as well as their spectral data and other references are provided in the review papers (4,5,8). Narceine enol lactones (101 and 102) are described in Refs. 87 and 90. 

Secophthalideisoquinoline enol lactones of type 128 were used by Klotzer et al. (95,103-105) for the synthesis of benzazepine system 129 which was further transformed to alkaloids of rhoeadine type. 

Secophthalideisoquinoline keto acids are postulated to be biosynthesized from phthalideisoquinoline metho salts via enol lactones. Such transformations occur easily in laboratory experiments (Section III,B,1). There are... 

It has been postulated that secophthalideisoquinoline ene lactams and hydroxy lactams are most probably artifacts of isolation resulting from the reaction of enol lactones or keto acids with ammonia during the extraction process. The hydroxy lactams are probably formed initially and then undergo dehydration to give ene lactams (5,8). For this reason, this section covers the hydroxy lactams in addition to the ene lactams. The hydroxy lactams are... 

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