Ring contraction of 4-oxo-1,3-dioxanes a new route to β-lactones

Triethyl Orthoformate

“…59 98% ee >95% ee (29) Selective monomethylation of arylacetonitriles results by reacting the substrates with trimethyl orthoformate and potassium tert-butoxide in methanol (eq 30). The methylation proceeds in fair to moderate yields but efficiency varies drastically with slight alterations in reaction parameters.…”