bicyclo[2.2.1]-hept-2-en-7-one (norborn-2-en-7-one) to yield a mixture of stereoisomeric alcohols, or respectively spiro-ethers, which can be separated by means of chromatography. The initially formed alcoholates were further reacted with diethylchlorophosphate to yield the respective chloro-substituted derivatives. Subsequent reductive cleavage of the chlorine-carbon bonds by lithium-powder in DME