Derivatives of vitaminD3 carrying an 8-carbon linker at C-11 terminating in an active ester were synthesized from commercial vitaminD3 using a disassembly–reassembly strategy. VitaminD3 was cleaved at the C6–C7 double bond and the ‘upper’ fragment was converted, via a series of reactions, to derivatives substituted at C-11 with an 8-carbon linker terminating in an ethyl ester. Reassembly with modified