BICYMANTRENYL CHEMISTRY .5. SUBSTITUTION-REACTIONS IN CP RINGS OF (CO)(3)MNC5H4C5H4MN(CO)(2)PPH3 COMPLEX

The complex (CO)(3)MnC5H4C5H4Mn(CO)(2)PPh3 (2) can be involved in elec trophilic reactions such as hydrogen-deuterium exchange with CF3COOD i n CH2Cl2 and acetylation with a MeCOCl-AlCl3 mixture. In both cases, t he substituent (D or MeCO) only enters the C5H4Mn(CO)(2)PPh3 ring. Met allation of 2 with BuLi (THF, -60 degrees C) occurs exclusively in the C5H4Mn(CO)(3) ring. Quenching of Li-containing derivatives with DMF r esults in a mixture of two isomeric aldehydes with the substituent in position 2 or 3. Reduction of 3-aldehyde with NaBH4 gives the correspo nding carbinol (6b). Metallation of the latter followed by quenching w ith DMF gives hydroxyaldehyde (CO)(2)PPh3MnC5H4C5H2(CH2OH)(CHO)Mn(CO)( 3).