Abstract: A process for preparing N-substituted amino acid esters having the formula (I): ##STR1## wherein R.sub.1 and R.sub.4, the same or different, are an alkyl, aralkyl, cycloalkyl or aryl group; and R.sub.2 and R.sub.3, the same or different,are an alkyl, aralkyl, aryl, heterocycle-alkyl, aminoalkyl or guanidylalkyl, by the reaction of .alpha.-amino acid esters with .alpha.-substituted carboxylic acid esters, under the condition of substantially free from solvent, which can afford their optical isomers in a good yield.

Abstract: A process for the preparation of .alpha.-hydroxyketones ##STR1## having a high purity in a good yield from a compound ##STR2## by rearrangement reaction in aqueous alkaline solution, where R.sub.1 and R.sub.3 each represent an alkyl, alkenyl or aryl group, R.sub.2 represents a hydrogen atom or an alkyl, alkenyl or aryl group, and X represents hydroxyl group or a halogen atom.

Abstract: According to the present invention, a radio apparatus has a section for receiving an analog signal and a digital angle-modulated carrier wave signal. The analog signal and digital angle-modulated carrier wave output of the receiver section are demodulated to provide first and second demodulated signals. A clock signal is regenerated from the output of either the demodulating means or receiver section. A control signal selectively operates a switch for passing either the first or the second demodulated signals. The regenerated clock signal controls the switch.