Simple Routes to Sarkomycin

Article abstract of DOI:10.1021/ja00329a038

Two synthetic routes to sarkomycin (6) are demonstrated.The first involves a 3-carbon annelation to form the spirocyclopentenone (2) followed by regiospecific γ-alkylation and subsequent manipulation of the side chain in 15 to give the sarkomycin ester adduct 18.The second route employs the itaconate-anthracene adduct 20 as the C-5 synthon in a tandem Michael addition-Dieckmann condensation between the anion derived from 20 and methyl acrylate.The reaction furnishes the diester 22, which, upon selective decarboxylation, gives rise to the sarkomycin precursors 18 and 23 (1:3).Flash vacuum pyrolysis of either isomer 18 or 23 yields (+/-)-sarkomycin ester 7 which is then hydrolyzed to the acid 6.