Monoterpenoids structure formation

Figure 5. Postulated formation of wine-lactone 10 from monoterpenoid acid 9A in analogy to dillether 12 formation from the structurally related chol 11.

Several new fascinating halogenated monoterpenoids, e.g. (20) and (21), have been isolated from red algae of Chondroccus species their structure suggests formation by enzymic addition of BrCl to myrcene followed by dehydrohalogena-tion. 

Subsequent Reactions of Strictosidine Classification and Structural Types of Indole Alkaloids Formation of the Major Indole Alkaloid Types Summary of Pathways Leading to Major Types of Monoterpene-Derived Indole Alkaloids Chemosystematic and Phylogenetic Application Monoterpenoid Indole Alkaloids of Pharmacologic Significance Vincamine... 

Altogether this means that in the general biogenetic formation of monoterpenoid indole alkaloids possessing the unrearranged skeletal system (173-175), the route leading to the sarpagine and ajmaline structures takes a course of its own (159 —> 157 158 —> 154 —> 22) before the formation of 4,21-... 

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