Ps. Aburel et K. Undheim, Rhodium(II)-carbenoid C-H insertion reactions in the synthesis of beta-oxospirane systems, J CHEM S P1, (12), 2000, pp. 1891-1896
A simple one-pot procedure is described for the preparation of spiro[4.4]no
nane-2,7-dione derivatives from open chain bis(alpha-diazoketones) by two c
onsecutive intramolecular Rh(II)-catalyzed carbenoid insertion reactions. W
ith 1-diazo-4-(3-oxocycloalkyl)butan-2-ones as substrates, the methodology
provides 2,7-dioxospiranes with a cyclopentane ring spiroannulated onto a f
ive-, six- or seven-membered cycloalkane.