Synthesis of 1,3-amino alcohols from 2-aza-1,3-dienes by reduction of 5,6-dihydro-2H-1,3-oxazines

Article abstract of DOI:10.1055/s-1991-26473

5,6-Dihydro-2H-1,3-oxazines 3, prepared from 2-aza-1,3-dienes 4, react with sodium in 2-propanol, giving tetrahydro-2H-1,3-oxazines 5. The acid hydrolysis of 5 leads to 1,3-amino alcohols 6 with three stereocenters. The reduction of 3 with lithium aluminum hydride affords N-alkyl derivatives of 1,3-amino alcohols 7 with four stereocenters. The stereochemistry of these compounds was established by X-ray crystallography of (4S*,5S*,6R*)-5-methyl-4,6-diphenyl-3-[(1R*)-1-phenylpropyl]tetra hydro-2H-1,3-oxazine (8).