N-chloro-succinimide; (neocuproine)Pd(OAc)2; sodium acetate in acetonitrile T=55°C; P=760.051 Torr; 24 h; Molecular sieve;

tetrabutylphosphonium iodide; Bu3SnI T=60°C; 5 h; other time, other components of catalyst; effect on the yield; Product distribution;

1: trimethyl-oxo-sulfonium iodide With sodium hydride in dimethyl sulfoxide T=25°C; 0.0833333 h; Inert atmosphere; 2: propionaldehyde in tetrahydrofuran; dimethyl sulfoxide 1 h; Inert atmosphere; 3: carbon dioxide in tetrahydrofuran; dimethyl sulfoxide T=40°C; P=760.051 Torr; 6 h; Inert atmosphere;

Co(III) salen-type in ethylene glycol dimethyl ether T=25°C; P=10500.8 Torr; 48 h; Title compound not separated from byproducts;

urea

2,5-dihydro-pyrrole hydrobromide T=200°C; P=36775.4 Torr;

RuHCl(CO)(bis-(2-diphenylphosphinoethyl)amine); potassium tert-butylate; hydrogen in tetrahydrofuran T=140°C; 10 h; Autoclave;