Enolates of thiabicyclic ketones as stepping stones towards synthesis of sulfur analogs of tropane alkaloids

Enantioselective deprotonation of the bicyclic, sulfur bridged ketone TBON (8-thiabicyclo[3.2.1]octan-3-one, 1) with chiral lithium amides is describe d. Enolization proceeds with high levels of selectivity with some bases (mo st notably with lithium (S)-N-diphenylmethyl-1-phenylethanamide 3d) and the subsequent reaction of the resulting non-racemic lithium enolate with acyl cyanides allows efficient Synthesis of sulfur analogs of tropane alkaloids (e.g., compound 8).