Barry C. Peterson

A novel, stereoselective synthesis of cis-4a (S), 8a(R)-decahydro-6(2H)-isoquinolones from meroquinene esters

Abstract Intramolecular cyclization of N-acylated meroquinene t-butyl esters in cold H2SO4 cleanly afforded cis-4a(S), 8a(R)-decahydro-6(2H)-isoquinolones with cmnplete stereocontrol in ⪢95% yield. Formation of the meroquinene esters from cinchona alkaloid autoxidation using an improved Doering protocol was accomplished in three steps with 85% overall yield.

Diastereoselectivity in the heterogeneous hydrogenation reactions of phosphorous substituted olefins

Phosphorous substituted methylenecyclohexane olefins show enhanced diasteroselectivity in heterogeneous hydrogenation reactions using Pd/C. A model system, derived from 4-t-butylcyclohexanone was used to explore the effects of solvent polarity and catalyst on the reduction reaction. It was found that olefins hydrogenated with catalytic Pd/C in polar solvents afford the highest diastereoselectivities (>15:1).

Diastereoselective conjugate addition approach to picenadol and oxygenated analogues

Horner-Emmons-Wadsworth reaction with 1,3-dimethyl-4-piperidone in water afforded an exocyclic enone, with minimal deconjugation of the double bond. Copper catalyzed conjugate addition with an aryl Grignard reagent then afforded an adduct with high stereocontrol. Wolff-Kischner reduction and deprotection proceeded to provide picenadol (1) in excellent overall yield. Access to oxygenated analogues of picenadol was also accomplished with this approach

A concise, stereoselective synthesis of picenadol

Abstract A four-step stereoselective synthesis of picenadol ( 1 ) is reported, 1,3-Dimethyl-4-piperidone ( 3 ) underwent Horner-Wadsworth-Emmons reaction under conditions that did not yield double-bond isomerization, followed by a directed 1,4-addition with an aryl cuprate. Reduction and deprotection then afforded ( 1 ).