text:  α @-@ <unk> with <unk> has been widely implemented in total synthesis . It is a key step in both the Holton Taxol total synthesis and the Wender Taxol total synthesis . Additionally , Forsyth implemented the transformation in his synthesis of the C3 @-@ C14 ( Substituted 1 @,@ 7 @-@ <unk> [ 5 @.@ 5 ] <unk> @-@ 3 @-@ ene ) System of <unk> acid . 
  