Synthetic study on naturally occurring acetylenic spiroacetal enol ethers: The first access to optically active 3,4-diacetoxy-2-formylmethylene- 1,6-dioxaspiro[4.5]decanes

Article abstract of DOI:10.1016/S0040-4039(99)00579-1

Optically active 3,4-diacetoxy-2-formylmethylene-1,6- dioxaspiro[4.5]decanes have been synthesized from an acyclic keto-alcohol possessing an unsaturated aldehyde part via intramolecular conjugate addition. The C3- and C4-stereogenic centers were introduced via Sharpless asymmetric dihydroxylation of an acyclic conjugated ketone with modified AD- mix-α in high enantioselectivity (96% e.e.). This is the first access to optically active spiroacetal 2-enol ethers.