Although numerous acyclic amidophosphites of type 1, 2 and 3 have been described very early, until recently no bicyclic compound like 4 was known.In a note published in 1977 (1), we have described the 2,8-dioxa-5-aza-1-phospha III bicyclo[3.3.0]octanes 4 and 5. In spite of their structural simplicity, they were, to our knowledge, the first phosphorus derivatives of this kind ever described, although the arsenic homologue of 4 has been known since 1970 (2).Such compounds were not obtained sooner due to two difficulties we met during our approach. (i) First the compounds tend to oligomerize quite easily, however the presence of substituents slows down the phenomenon. (ii) The second difficulty comes from the fact that these compounds can add any molecule with a mobile hydrogen (ROH, R 2 NH etc...) leading mainly to phosphoranes with a P-H bond 6 (X = RO-, R 2 N-).These two observations show that double cyclisation confers on the bicyclic phosphanes particular properties and we were prompted to continue our research in this field.We have described recentlyfour new bicyclic phosphanes 7, 8 9 (3) and 10 (4) while three interesting articles have been devoted to 10 (5), 4 (6) and 11 (7).