An Unexpected Asymmetric Reduction of 4‐(1‐Nitro‐2‐oxocyclododecyl)butan‐2‐one. Determination of the absolute configuration of (‒)‐15‐hexadecanolide

Reduction of the carbonyl group in the side chain of 4‐(1‐nitro‐2‐oxocyclododecyl)butan‐2‐one ( 3 ) with organoboron complexes are influenced by the chiral center, in 4‐position with respect to the carbonyl C‐atom, to which the NO 2 group is attached, a rare type for an asymmetric reduction. Independent of the ( R )‐ or ( S )‐configuration of the Alpine ‐ Hydride , (+)‐ 3 is reduced only to the (15 S )‐nitrolactone (+)‐ 5 and, after subsequent transformations, to (+)‐(‐ S )‐15‐hexadecanolide ((+)‐ 1 ), enantiomer of the naturally occurring (−)‐ 1 .