Diastereoselectivity in non-aldol aldol reactions: silyl triflate-promoted Payne rearrangements

The non-aldol aldol process exhibits diastereoselectivity such that one isomer of a secondary epoxy silyl ether gives only the expected ketone product while the other affords both ketone and aldehyde. We present evidence for a novel silyl triflate-promoted Payne rearrangement of silyloxy epoxides, e.g. D3↔E3. Additional examples of the non-aldol aldol process are presented including cyclic examples and one in which an aryl ring participates to give unusual products.