Spiro[4.4]non- and spiro[4.5]dec-2-ene-1,6-diones [2; n = 0 and 1] wer
e prepared in moderate to high enantiomeric purities via asymmetric al
lylation of enamines 6 and ketal derivatives 7 and 8 formed from keto-
esters 5, followed by a carbanionic cyclization process.