Abstract
Reaction of NaMn(CO) 5 with trans-1-bromopenta-2,4-diene in tetrahydrofuran at -78°C gives (η 1 -2,4-pentadienyl)Mn(CO) 5 (1) in excellent yield. Compound 1 undergoes η 1 → syn-η 3 → η 5 transformation and, yields (syn-η 3 -2,4-pentadienyl)Mn)(CO) 4 (2) and (η 5 -pentadienyl)Mn(CO) 3 (3), respectively. The reactions of 1 with the electrophiles tetracyanoethylene (TCNE) and sulfur dioxide (SO 2 ) were investigated. Compound 1 undergoes a [4 + 2] cycloaddition with TCNE and an insertion reaction with SO 2 . The product are characterized by elemental analysis and spectroscopic data. © 1987.