Careful A-ring substructure analysis for taxol has been carried out an
d a practical synthesis to all emergent substructures, viable as A-rin
g building blocks, has been developed. The synthesis starts from 2-met
hyl-1,3-cyclohexanedione and enters via ketalized trimethylvinyltrifla
te and ketalized trimethylester to trimethylketoalcohol(s) with the hy
droxyl group protected.