2-(Penta-1,3-dienyl)oxazolidines: Synthesis of hydroxylated piperidines by a stereoselective Diels-Alder reaction

Article abstract of DOI:10.1016/S0040-4020(01)86312-2

Hexa-2,4-dienal condensed with (-)-ephedrine to give predominantly the oxazolidine 4, which underwent a stereoselective Diels-Alder reaction with benzyl nitrosoformate to give the cycloadducts 9 and 10 in a ca 5:2 ratio. Further transformations of 9 to give the optically active mono- and tri-hydroxypiperidine derivatives 11 and 15 have also been performed.