1: 32 percent Spectr. / hexamethyldisilazane de sodium / pentane / 1.) -15 deg C, 1.5 h; 2.) rt., 1 h 2: CDCl3 / 24 h / Ambient temperature View Scheme

sodium hexamethyldisilazane multistep reaction: 1.) pentane -15 deg C; 2.) methanol-triethylamine, reflux; studied: the stereochemistry (E or Z) in the addition reaction of ketene alkylsilyl acetals with chloro-, chloromethyl- and chlorophenyl carbenes; Product distributionMechanism;