The bromination product (11) of 1, 2-diethoxyethylene (I) has been converted to bromodiethoxyethylene (111), which is found to add either ethanol or water in both possible directions. The intermediate addition product (IV), identical with the product from the addition of hydrogen bromide to ethoxyketene acetal, is found to be too unstable to isolate. I11 may be reconverted to I via the lithium derivative or to the dibromo derivative (VIII) of I. The ...