Etudes cinétiques en série alicyclique‐I Substitution nucléophile bimoléculaire réversible, par les ions iodures, des bromures de cyclobutyle, cyclopentyle, cyclohexyle, et cyeloheptyle

Abstract

Etudes cinCtiques en sC& alicyclique -I Bull. SOC. Chim. Belg., 61, pp. 427-451, 2 fig., 1952 Substitution nuclhophile bimolCculaire rbversible, par les ions iodures, des bromures de cyclobutyle, cyclopentyle , cyclohexyle, et cyeloheptyle Par P.J.C. FIERENS (*) et P. VERSCHELDEN (Bruselles) SUMMARY. -Arrhknius parameters and heat of reaction are determined for reversible S,2 reactions, involving alicyclic bromides : /CH2 CH2 (CH2)n I + I-z ( C H 2 4 + Br-'CH-Br CH-I Lithium iodide and anhydrous acetone (as solvent) are used. The following bromides are studied : n = 2 : cyclobutyl bromide E, = 24,5 Kcal/mole PZ = 9 . 0 1 0 ' 0 AH = 4,6 Kcal/mole E, = 20,4 Kcal/mole AH = 1,8 Kcal /mole E, = 23,s Kcal/mole AH = 1,4 Kcal/mole E, = 20,4 Kcal/mole AH = 2,2 Kcal/rnole n = 8 : cyclopentyl bromide PZ = 2,o 1010 n = 4 : cyclohexyl bromide

A Synthesis of Oseltamivir (Tamiflu) Starting from d-Mannitol

“…Our own interest in the subject led us to pursue a novel synthetic approach that entailed a construction of an acyclic precursor and its cyclization at a later stage to form the Tamiflu skeleton. Our reasoning was that acyclic intermediates would be more amenable than cyclic ones in the required chemical manipulations such as O→N substitutions . Recently, a synthesis of Tamiflu was reported that employed a synthetic strategy quite analogous to our own, although they differ in detailed executions .…”