Kinetic control carbonyl basicity

Methyldecamine (174) was synthesized from pelletierine and the alkali-insoluble amide 170 by Hanaoka et al. (81). Decamine (18) was synthesized by Lantos et al. by the kinetically controlled condensation of pelletierine with biphenyl aldehyde (169) which afforded the cfs-quinolizidone (173) in 50% yield. Reduction of the carbonyl group with Henbest catalyst followed by alkaline hydrolysis produced the undesirable trans-fused quinolizidols as a major product. However, hydrogenation with platinium catalyst in an alkaline solution afforded the less stable cis-fused axial carbinol, which on cyclization followed by a mild basic hydrolysis yielded decamine (18). 

Kinetics Proton transfer catalyzes many reactions. Proton transfer between heteroatom lone pairs is very fast, often at the diffusion-controlled limit. Under reversible (equilibrium) conditions, the most acidic proton is removed preferentially. However, if the deprotonation is done under irreversible conditions, the proton removed is determined by kinetics, not thermodynamics (Section 9.3). Anion basicity always competes with nucleophilicity. Proton transfer is slow enough between organometallics and protons adjacent to carbonyls (carbon bases with carbon acids) that addition of the organometallic to the carbonyl is the dominant process, path AdN. 

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