SYNTHESIS, CONFIGURATIONAL ASSIGNMENT, AND CONFORMATIONAL-ANALYSIS OF BETA-HYDROXY SULFOXIDES, BIOISOSTERES OF OXISURAN METABOLITES, AND THEIR O-METHYL DERIVATIVES

Synthesis, configurational assignment, and conformational analysis of diastereoisomers of 2-(methylsulfinyl)-1-(2-quinolyl)ethanol, 3a, 2-(methylsulfinyl)-1-(1-isoquinolyl)ethanol, 3b, 2-(methylsulfinyl)-1-(2-pyrazyl)ethanol, 3c, and their O-methyl derivatives 4a-c are reported. The configurational assignment and conformational analysis of the two diastereoisomers of beta-hydroxy sulfoxides and beta-methoxy sulfoxides have been carried out from the observed vicinal coupling constants using the molecular mechanics force field (MMX) and the Altona relationship as fundamental tools. The conformational equilibrium is explained in terms of polar and steric factors. Of significant importance was the role of intramolecular hydrogen bonding in the RS/SR isomers of beta-hydroxy sulfoxides.