RESUMEN
A highly stereoselective construction of 2,6-cis-disubstituted tetrahydropyrans was achieved by using an intramolecular amide enolate alkylation with KHMDS. The efficiency and practicality of this methodology was successfully demonstrated in the total synthesis of (-)-centrolobine (1).
Asunto(s)
Amidas/química , Piranos/química , Alquilación , Estructura Molecular , Piranos/síntesis química , EstereoisomerismoRESUMEN
A series of C(18)-guggultetrol stereo isomers and C(18)-phytosphingosine regio/stereo isomers were synthesised in a stereoselective fashion involving metal mediated fragmentation, stereoselective reduction, 1,4 O â O silyl migration, and Grubbs' cross metathesis as key steps. d-Fructose was used as a raw material for the preparation of all the analogues. The isophytosphingosine derivatives were evaluated against their 5-LOX (5-lipoxigenase) inhibitory activity.
Asunto(s)
Araquidonato 5-Lipooxigenasa/metabolismo , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/síntesis química , Alcoholes Grasos/síntesis química , Alcoholes Grasos/farmacología , Fructosa/química , Esfingosina/análogos & derivados , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Alcoholes Grasos/química , Estructura Molecular , Esfingosina/síntesis química , Esfingosina/química , Esfingosina/farmacología , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
A stereoselective methodology was developed for the construction of C-spiro-glycosides in two steps involving bromonium ion activated solvolytic ring opening of sugar derived 1,2-cyclopropanecarboxylates followed by a one-pot dehydrohalogenation, intramolecular hetero-Michael addition (IHMA) and ester hydrolysis. The obtained spirocyclic lactols were further converted to enantiomerically pure spirolactones.