78481-70-6Relevant articles and documents
Synthesis and Reactions of 1--2-methyloxiranes with Nitrogen Nucleophiles
Avasthi, Kamlakar,Knaus, Edward E.
, p. 375 - 382 (2007/10/02)
Reaction of 2(3,4)-pyridinecarboxaldehydes (5) with ethylidenetriphenylphosphorane afford a mixture of stereoisomers Z-(6) and E-1--1-propenes (7). m-Chloroperbenzoic acid oxidation of 6 and 7 yields a 60 : 40 mixture of Z-(8) and E-1--2-methyloxiranes (9).The regiospecific reaction of Z-isomers 8a-c with cyclic amines as piperidine give rise to threo-1-hydroxy-1--2-(1-piperidino)propanes (10) while the E-isomer 9a yields erythro-11.On the other hand, the E-isomers 9b and 9c having 1-oxido-3(4)-pyridinyl substituents afford erythro-12 resulting from attack by piperidine at C-1 of the oxirane.Reductive deoxygenation using 10 percent palladium on charcoal and hydrogen gas effectively removed the N-oxide substituent from the threo-10 and erythro-11β-aminoalcohols.Dilute solution ir spectroscopy indicated the existence of strong intramolecular hydrogen bonding in the β-aminoalcohols 10 and 11.The assignment of relative configuration of diastereoisomers 10 and 11 was based on the magnitude of the vicinal coupling constant J where J threo is greater than J erythro.
