title: Stereochemical control factors in the Hantzsch thiazole synthesis: a Hammett substitution correlation analysis.
abstract: [reaction--see text] It is possible to correlate the distribution of stereochemical products produced during a Hantzsch thiazole synthesis according to the Hammett free-energy equation. This analysis confirms the presumed control of the rate of epimerization during thiazole formation due to stabilization of a cationic transition state intermediate during dehydration of the thiazoline ring system. In the chemical system under study, the stereochemical outcome of the reaction also appears to occur according to a kinetically controlled protonation of a thiazoline tautomer.
authors.affiliation: Roche Research Center, Nutley, New Jersey, 07110-1199, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Qiao
authors.forename: S S
authors.initials: SS
authors.lastname: So
authors.forename: R A
authors.initials: RA
authors.lastname: Goodnow