Preparation of pyrrolidine and pyrrolidin-2-one derivatives

A process for the preparation of pyrrolidine compounds of the formula:

• ##STR7## in which n is 1, 2 or 3 inclusive, R.sub.1 and R.sub.2, which may be the same or different, are hydrogen or alkyl having 1 to 3 carbon atoms and the asterisk indicates the center of asymmetry of the molecule either as separated enantimoers or as mixture, comprising the steps of (1) reacting .gamma.-amino-.beta.-hydroxybutyric acid in the form of an enantiomer or of a mixture of enantiomers, under anhydrous conditions with a silylating agent, (2) cyclizing the product obtained by heating and (3) then reacting said cyclized product in the presence of an alkaline hydride with an aliphatic acid ester halide of the formula Hal(CH.sub.2).sub.n COOR, in which Hal is bromine, chlorine or iodine, R is alkyl containing 1 to 4 carbon atoms trichlorophenyl, nitrophenyl or trichloroethyl and n has the same meaning as above, to give a silyl compound of the formula:
• ##STR8## in which R' is methyl or ethyl and n, R and the asterisk have the same meanings as above, (4) then hydrolizing compound (II) to give the corresponding 4-hydroxy compound and (5) reacting said hydroxy compound with a compound of the formula R.sub.1.NH.R.sub.2, in which R.sub.1 and R.sub.2 have the same meanings as above.