RESUMEN
Synthesis of the A/D/E-ring core compounds of maoecrystal V was achieved. The key Diels-Alder reactions between tricyclic α-methylene lactones and Kitahara-Danishefsky dienes afforded the spirocyclic core compounds in a regioselective and stereoselective manner.
Asunto(s)
Lactonas , Estereoisomerismo , Lactonas/química , Lactonas/síntesis química , Reacción de Cicloadición , Técnicas de Química Sintética , Diterpenos/síntesis química , Diterpenos/química , Compuestos de Espiro/química , Compuestos de Espiro/síntesis química , Estructura MolecularRESUMEN
Thelepamide, an unique ketide-amino acid isolated from a marine annelid worm Thelepus crispus, has a unique oxazolidinone ring derived from cysteine, glycine and valine. Rareness in nature as well as promising bioactive possibility make the oxazolidinone ring an attractive synthetic target. The hydroxy oxazolidinone fragment of thelepamide was prepared by acid-catalysed N,O-acetal formation between a ketoamide and formaldehyde. Lactone-carbonyl selective isopropyl addition to an oxazilidine-dione under Grignard conditions also forms the target compound.