Retro-Dieckmann condensation

Besides the Michael addition-initiated domino reactions presented here, a multitude of other anionic domino reactions exist. Many of these take advantage of an incipient SN-type reaction (for a discussion, see above). In addition to the presented SN/Michael transformations [97, 98, 100], a SN/retro-Dieckmann condensation was described by Rodriguez and coworkers, which can be used for the construction of substituted cycloheptanes as well as octanes [123]. Various twofold SN-type domino... 

The reaction starts with the formation of a mixed anhydride and an acetate on treatment with an excess of acetic anhydride at 80 °C. There follows a Dieckmann condensation to give 2-590 and an intramolecular rearrangement/Michael addi-hon/retro Michael addition to afford the desired tetracyclic compound 2-592 via 2-591 in an overall yield of remarkable 92%. 

Michael addition, followed by an intramolecular aldol condensation to provide the seven-membered ring. Subsequent retro-Dieckmann reaction, dehydration, and ester saponification provide the bicyclic product in 98% yield. A related cascade reaction was recently reported by the same research group in which the reactions of various allylic halides with cyclopentanone derivatives provide seven-membered rings. ... 

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