The unexpected reorganizations of a beta-lactone aldolate to 1,3-dioxan-4-ones in the reaction of 4-(1-methylethyl)-3-[(phenylthio)methyl]-1-oxetan-2-one lithium enolate with acetaldehyde

The Lithium enolate 4-(1-methylethyl)-3-[(phenylthio)methyl]-1-oxetan-2-one (1), generated from the conjugate addition of lithium thiophenolate to ct- methylene-beta-lactone 2, reacts with acetaldehyde to give the 1,3-dioxan-4 -ones 3 and 4 as unexpected aldol products. These products result from unus ual aldol reorganization processes, which entail a complex cascade of aldol additions, retroaldol cleavages and translactonizations, The configuration s of the products have been determined by NOE experiments.