Selective Hydrogenation of 4,5-Dihydro-1,3-oxazin-6-ones to Carbaldehyde Derivatives; Chemical Differentiation between Acylazetidin-2-ones and the Corresponding Isomeric Oxazin-6-ones
Catalytic hydrogenation of optically active and non-active dihydro-oxazin-6-ones unexpectedly led to preferential reduction of the carbonyl group with ring-opening yielding carbaldehyde derivatives.This reaction resolved a structural problem by leading to