Cob(I)alamin als Katalysator. Retention der Konfiguration bei der reduktiv-protonenuebertragenden Spaltung der Co,C-Bindung eines Alkylcobalamins

Article abstract of DOI:10.1002/hlca.19800630632

Using catalytic amounts of cob(I)alamin (see Scheme 1) in aqueous acetic acid (-)-α-pinen (1) and (-)-β-pinen (2; s.Scheme 3) have been reduced.A large excess of metallic zinc served as electron source.The saturated products 5-8 (see Scheme 3) and the mechanistic aspects of their generation are discussed.The relative amounts of cis- (5) and trans-pinane (6) lead to the conclusion that the reductive cleavage of the Co, C-bond accompained by H⁺ transfer in an alkylcobalamin occurs with retention of configuration.This result is in agreement with the corresponding cleavage of the Co,C-bond of an alkylcobalt complex <9>.