The synthesis of (−)-varitriol and (−)-3′-epi-varitriol via a Ramberg-Bäcklund route

A concise route to the anti-tumour natural product (−)-varitriol, together with its novel isomer (−)-3′-epi-varitriol, is described using a Horner-Wadsworth-Emmons (HWE)/conjugate addition/Ramberg-Bäcklund sequence as the cornerstone. The flexibility of the synthetic route has been demonstrated by the preparation of novel varitriol analogues.