Low-temperature vinylcyclopropane rearrangement in the total synthesis of (-) - specionin

The microbial oxidation of arenes to the corresponding cis-diols has been shown to be a convenient source of optically pure diols which can be used as synthons in asymmetric synthesis of complex, highly oxygenated molecules. The utility of such synthons has been demonstrated by the total synthesis of (-)- Specionin 1. A key transformation in this sequence is a low-temperature rearrangement of vinylcyclopropane 59 to diquinanes 61 and 62. Of additional merit is the development of an efficient preparation of enone 56 from cis arene diol 66.