Synthesis, stereostructure, and conformations of novel bi- and trifunctional (+)-isomenthone derivatives

[reaction: see text] Following protection, keto alcohols 4 [from (+)-isomenthone] undergo reduction to 1,3-diol 6 (S configuration at the new stereocenter). Organometallic C-nucleophiles add to the carbonyl with the same facial selectivity as hydride, providing multifunctional derivatives, e.g., 8 and 9, with five contiguous stereocenters. The side chain hydroxyl of 4 is elaborated into amino and amide derivatives (e.g., 12). Structural analysis shows that 6, 8, 9, and the precursor to 12 (10) all adopt triaxial solid-state conformations.