Domino synthesis of carbo- and heterocycles involving a 1,3 or 1,4 C→O silyl migration

This account shows that a silyl-substituted carbanion may be looked upon as a latent dianion which, in the reaction with biselectrophiles, yields ring-closure products. The biselectrophile is normally an epoxide carrying a remote leaving group. The carbanion will open the epoxide and allow for a C -> O silyl shift thus generating the new carbanion. This then reacts with the second functional group of the biselectrophile. The flexibility of the approach is demonstrated by using various acceptor groups on the initial carbanion 1 (SR, SiR3, CN) while the range of biselectrophiles includes epoxyalkyl tosylates, bisepoxides, epoxy-aziridines, vinyl-epoxides, and, for heterocyclic synthesis, bromoalkyl isocyanates. Instead of the epoxide, an ester group may act as electrophile. 1 Introduction 2 Cyclopropanes by Homo-Peterson Reaction 3 Epoxyalkyl Tosylates as Biselectrophiles 3.1 Synthesis of Cyclobutanols 3.2 Synthesis of Cyclopentanols 3.3 Larger Carbocyclic Rings 4 Bisepoxides as Biselectrophiles 5 Vinylepoxides as Biselectrophiles 6 Phthalates as Biselectrophiles 7 Bromoalkyl Isocyanates as Biselectrophiles 8 Divertimento! 9 Conclusion.