Mitosanes, structure

In this review, the trivial names mitosane and mitosene [14] (Fig. 1) will be used to describe various mitomycin structures. For example, mitomycin C is 7-amino-9a-methoxymitosane. It should be noted that the numbering of a mitosane differs from the systematic numbering used in Chemical Abstracts for azirino[2, 3 3,4]pyrrolo[l,2-a]indoles, wherein the aziridine nitrogen is the starting point. 

Interest in the synthesis of the mitomycins has resulted in a variety of procedures for the preparation of pyrrolo-indoles and related structures. Now Ban and his colleagues have reported a biomimetic route to the mitosane skeleton which involves a novel retro-aldol type of ring-opening reaction followed by a trans-annular cyclization (Scheme 102). A mitosane-like compound is available via... 

Fig. 1. The structure of mitosane showing relative stereochemistry as established by Tulinsky (J. a. C. S. 84, 3188, 1962). Notations X, Y, Z indicate positions of hydrogen atoms which are substituted to complete the antibiotic molecule and yield mitomycin A, B, C and porfiromycin...

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