" Institute of General Food Chemistry, Technical University of Lédi, PL-90-924 Lodi, Stefanowskiego 4/10, Poland Received 10 December 1996 trans-3-Carboxy-2- dicthoxyphosphorylcyclopentanone (11), a key precursor of sarkomycin I, has been synthesized in the rhodium (II) acetate promoted cyclization of diethyl 1-diazo-2-oxohept-6- ene phosphonate (9), followed by transformation of the 3-vinyl moiety into the 3-carboxylic ...