Preparation of Novel Polycyclic Heterocycles Using a Tin(II) Chloride Dihydrate-Mediated Deacetalisation-Bicyclisation Sequence

Tin(II) chloride dihydrate-mediated deacetalisation- bicyclisation procedures for the construction of novel polycyclic heterocycles from amides possessing a pendant acetal group are re- ported. Optimisation and scoping studies are described; using this methodology, a range of known, and novel, ring-fused heterocyclic systems have been prepared, some in enantiomerically pure form.