C-STANNYLMETHYLATED N-ACETYL-AMINOMALONIC AND N-FORMYL-AMINOMALONIC ACID-DERIVATIVES

Tin compounds of the type Me(3)SnCH(2)C(NHCOR) (COOEt)(2) (1: R = CH3; 2: R = H) are synthesized by reaction of acylaminomalonates with iodo methyl trimethylstannane. The halogenation of 1 and 2 yields the halos tannylsubstituted compounds Me(3-n)X(n)SnCH(2)C(NHCOR)(COOEt)(2) 3-6 ( R = Me, H; n = 1, 2; X= Cl, Br). The decarbethoxylation (KRAPCHO react ion) of 1 and 2 gives ethyl 3-(trimethylstannyl)-N-acyl alaninates (7 and 8). With one equivalent KOH 1 and 2 are transformed into the monoe thyl malonates of the type Me(3)SnCH(2)C(NHCOR)(COOH)(COOEt) (9: R = C H3), which convert simultaneously under decarboxylation into 7 and 8 a nd by cyclisation under elimination of methane into the 1,2-oxastannol ane derivatives 10 and 11. IR, NMR data and the determination of the c rystal structure reveal for MeBr(2)SnCH(2)C(NHCOCH3)(COOEt)(2) (5) hex acoordinated tin by intramolecular coordination of the amide-CO and on e of the ester-CO groups.