Abstract Monogermylated ketenes, R (Et 3 Ge) C C O, have been prepared by the Wolff rearrangement of carbenoids, Et 3 GeC̈COR, generated by the copper-catalyzed decomposition of the corresponding α-(triethylgermyl) diazo ketones in hexane. In contrast, triethylsilyldiazoacetone decomposes over copper by another reaction scheme to give, unexpectedly 1, 1-diethyl-3, 5-dimethyl-2-oxa-1-sila-3-cyclopentene. The copper- ...
