Ochotensine type

A fascinating contrapolarization-driven reaction is the conversion of a protoberine skeleton to an ochotensine-type alkaloid [211], The quinomethide carbon in the seco intermediate assumes a -character which is made possible by electron supply from the oxy substituent at the meta position. Note the C-N bond cleavage step entrusts this carbon an acceptor role. 

The ochotensine-type base (173 X = H2) has been obtained by Stevens rearrangement of the non-phenolic AT-methyltetrahydroprotoberberinium salt (172) with methyl sulphinyl carbanion (Scheme 19). Details have appeared of the benzocyc-lobutenyl route to (173 X = CH2) (c/. Vol. 4). The mass-spectral fragmentation pattern of various fumariline type alkaloids has been studied. ... 

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