Acetals bicyclic. hydrogenolysis

Although not directly related to this article, a brief summary of the hydrogenolysis of bicyclic acetals, a synthetically useful reaction, is given. 

Scheme 13.1 Formation and hydrogenolysis of bicyclic acetals in the hydrogenation of a cyclic enol ether 1.

The tandem cycloaddition of nitroalkene 394 (Scheme 16.77) produces a tetracyclic nitroso acetal 397 with up to six new stereogenic centers in just two steps. Hydrogenolysis reveals a bicyclic amino diol 398, which may react further, for example, forming tetracyclic lactam 399. AU of the six newly formed stereogenic centers may potentially remain in the hydrogenolysis products, such as 398. It is this dramatic increase in complexity that makes the tandem, double-intramolecular nitroalkene cycloaddition so attractive. 

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