Methyleneketenes and methylenecarbenes. VIII. Pyrolysis of methoxyacetylene

Abstract

LFlash vacuum pyrolysis (600°) of 5-methoxymethylene-2,2-dimethyl-1,3-dioxan-4,6-dione (1) gives either methoxymethyleneketene (3) or decomposition products considered to be formed from methoxyacetylene. Pyrolysis of methoxyacetylene gives a complex mixture of products, including methylketene, ketene, formaldehyde, acetylene, ethylene and ethane. A convenient procedure for the preparation of methylketene and its dimer is also described.