Synthesis of the bis-spiroacetal C-25-C-40 moiety of the antimitotic agent spirastrellolide B using a bis-dithiane deprotection/spiroacetalisation sequence

Abstract

Use of a bis-dithiane deprotection-tandem bis-spiroacetalisation sequence was key to the successful synthesis of the [5,6,6]-bis-spiroacetal of the antimitotic agent spirastrellolide B, achieved in a highly convergent fashion involving successive dithiane alkylations.