Synthesis of spiro[isoquinoline-4,4′-pyran]-3-imines

Stereoselective Synthesis of Hexahydro-1H-spiro[isoquinoline-4,4′-pyran] Scaffolds through an Intramolecular Prins Cascade Process

“…Furthermore, tetrahydroisoquinolines are privileged structures in medicinal chemistry and are prevalent in a large number of therapeutic agents and naturally occurring molecules . However, a few methods are reported for the synthesis of spiro­hexa­hydro­iso­quinoline derivatives; hence there is a great demand for the development of novel synthetic strategies for the stereoselective construction of spirocycles.…”

Efficient Synthesis of 4-(3-Fluoro-5-{[4-(2-methyl-1H-imidazol-1-yl)benzyl]oxy}phenyl)tetrahydro-2H-pyran-4-carboxamide, a Novel 5-Lipoxygenase Inhibitor

“…dium iodide and 15-crown-5, 5,9 and use of a phase-transfer catalyst. 10,11 The results are summarized in Table 1. Phase-transfer catalysis conditions 10 (entry 9) gave alkylated intermediate 15 and dimer 16 in addition to the desired pyran 13 (Scheme 4).…”

“…Phase-transfer catalysis conditions 10 (entry 9) gave alkylated intermediate 15 and dimer 16 in addition to the desired pyran 13 (Scheme 4). 11 Among the reaction conditions tried, the use of sodium hydride in DMSO (entry 8) gave 13 with the highest yield (75%). The reaction was reproducible (5 runs, 1-25 g scale, 69-82%), and the product was obtained in high purity as solids without the need of purification by column chromatography.…”