Eschenmoser sulfide contraction
Organic reaction method / From Wikipedia, the free encyclopedia
The Eschenmoser sulfide contraction is an organic reaction first described by Albert Eschenmoser for the synthesis of 1,3-dicarbonyl compounds from a thioester.[1][2][3] The method requires a base and a tertiary phosphine. The method is of some relevance to organic chemistry and has been notably applied in the vitamin B12 total synthesis.
A base abstracts the labile hydrogen atom in the thioester, a sulfide anion is formed through an episulfide intermediate which is removed by the phosphine.[4]