Approaches to the Total Synthesis of Calycotomine, a Widespread 1-Hydroxymethyl-Substituted Simple Tetrahydroisoquinoline

Abstract

1-Hydroxymethyl-substituted tetrahydroisoquinolines are scarce in nature; the widespread alkaloid calycotomine is its most prominent example. The different total syntheses of this natural product, used as test ground for the development of novel synthetic methodologies during the last forty years, and those of some structurally related precursors, are reviewed.

DDQ-Promoted Mild and Efficient Metal-Free Oxidative α-Cyanation of N-Acyl/Sulfonyl 1,2,3,4-Tetrahydroisoquinolines

“…We next turned on our attention to a short and efficient formal total synthesis of (±)-calycotomine ( 9 ) to prove the synthetic utility of this method (Scheme 3). Calycotomine ( 9 ) is hydroxymethyl THIQ alkaloid and was isolated from many plants including Calycotome spinosa Link, Leguminosae, Cystius proliferus , Acacia concinna , and mainly genus Genista [34,35,36,37,38]. This natural product was found to exhibit an antimicrobial activity with minimum inhibitory concentration (MIC) MIC 2–8 mg/mL against Enterobacteriaceae and Pseudomonas aeruginosa .…”

β-Phenylethylamines and the isoquinoline alkaloids

“…Oxidative cyclisation of the resulting alkyne 35, promoted by silver iodide, afforded the pyrrole 36, which was hydrogenated to 37. 21 Approaches to the synthesis of salsolidine, 22 of carnegine 23 and of calycotomine, 24 and the asymmetric synthesis of isoquinoline alkaloids in general 25 have been reviewed, as have syntheses of the azaoestrane 38 26 and the diazaoestrane 39, 27 which are complex tetrahydroisoquinolines.…”

Five-membered oxaza heterocyclic compounds on the basis of epoxides and aziridines

“…Syntheses of numerous natural compounds, especially enantiomerically pure derivatives, utilize oxazolidinones as building blocks. The chemical behavior and possible applications of these compounds were analyzed in a number of review articles [2,3,12,13,16,26,[32][33][34][35]. New possibilities in using chiral 1,3-oxazolidin-2-one derivatives (Evans chiral auxiliaries) were reported [36]; they were brought into various reactions (alkylation, aldol condensation, Diels-Alder reaction, etc.…”