Salicylamide condenses with y,6-or G&-unsaturated aldehydes to give cyclic amidals which readily undergo diastereoselective mercury(n)-mediated amidocyclization. The resulting products serve. as versatile intermediates for further elaboration as nitrogen heterocycles. Diastereoselcctive electrophilic heterccyclization reactions are commonly employed to control the relative stereochemistry in cyclic and, via cleavage of the heterocycle, in acyclic compounds.3 We have been interested in the consequences of double sterecdifferentiation4 in electrophilic amidocyclizations, particularly as it relates to the design of practical auxiliaries to control the stereochemical course of the cyclization. We have recently reported amidomercuration cyclizations that are directed by a phthalimide-derived auxiliary as a route to vicinal aminoalcohols. The stereogenic amidal center provides the dominant influence on the stereochemical course of these cyclizations.6 We now wish to report our preliminary investigations into the utility of the salicylamidederived amidal auxiliary as a stereochemical directing group for the conversion of unsaturated aldehydes into a variety of substituted N-acyl pyrrolidines and piperidines. Salicylamide undergoes acid catalyzed reaction with 4-pentenal or .5-hexenal under the conditions of azeotropic removal of water (cat TsOH / CHC13 / -H20) to yield the crystalline amidals 1 and 2 (70-85%). The cyclizations of these parent substrates assess the sense and strength of the stereogenic amidal center in directing the stereochemical course of the C-N bond construction. Amidal 1 undergoes rapid cyclization mediated by mercuric acetate/mercuric trifluoroacetate (a. 1.5 eq of a 1: 1 mixture of Hg(OAc)z-Hg(@CCF3)2 / CH3CN / 250 / 10 min; b. aq NaCl), a mixture of mercury(I1) salts that we found to be effective in the phthalimide cyclizations. The intermediate organomercurial chloride can be reductively cleaved (2 eq LiRti / THF / -78O) to give a 12.4: 1 2 03.4 t : 12.1 ram vans-4 cis:truns ratio of diastereomeric amidals in 90% yield. Pure diastereomer cis3 can be isolated by chromatography and recrystallization. Alternatively, the organomercurial intermediate can be efficiently cleaved by iodine (2 eq 12 / CH2C12 / 00 / 99%). Similarly, unsaturated amidal 2 undergoes facile cyclization/reduction to give a 1: 12.1 cis:nanr mixture of crystalline amid& in 86% yield. The degree of stereoinduction is comparable in the parent