B. Brown et Ls. Hegedus, OPTICALLY-ACTIVE CYCLOBUTANONE CHEMISTRY - SYNTHESIS OF (-)-CYCLOBUT-A AND (+ -)-3'-EPI-CYCLOBUT-A/, Journal of organic chemistry, 63(22), 1998, pp. 8012-8018
The carbocyclic nucleoside analogues (-)-cyclobut-A and (+/-)-3'-epi-c
yclobut-A were synthesized utilizing photolysis of the (benzyloxymethy
l)(methoxy) chromium carbene complex 4 with optically active ene-carba
mate 5 to produce the corresponding optically active alpha,alpha-disub
stituted cyclobutanone 6. Stereoselective removal of the alpha-ethoxy
group with inversion gave cyclobutanone 7, which was converted by exis
ting methodology to the title compounds.