E. Bandini et al., Synthesis of perhydrooxazinones from 2-aza-3-trimethylsilyloxy-1,3-butadiene. A general route to 3,3-disubstituted-beta-hydroxy acids, SYNLETT, (11), 1999, pp. 1735-1738
1-Phenyl-2-aza-3-trimethylsilyloxy-1,3-butadiene reacts with aliphatic, aro
matic and cyclic ketones to give in good to excellent yields 6,6-disubstitu
ted-1,3-perhydro-oxazin-4-ones which, in turn, have been readily converted
into beta -hydroxy carboxylic acids.