| Abstract
| - The aldol reaction of tetrahydro-4H-thiopyranone with 1,4-dioxa-8-thiaspiro[4.5]decane-6-carboxaldehyde(I) gives four possible diastereomeric adducts (II). Aldol reactions of I with each of the diastereomersof II and their corresponding methoxymethyl ethers III via the Ti enolates were investigated. Usingracemic reactants, reactions with II proceeded with high levels of mutual kinetic enantioselection (MKE)and double stereodifferentiation (DS) to give one of the eight possible bisaldol adducts. Similar reactionsof III proceeded with low levels of MKE and DS and gave two bisaldol adducts, one from each of thepossible combinations of enantiomeric reactants. By extension, 11 of the 20 possible diastereomers ofthe bisaldol adduct could be obtained selectively. These adducts are useful for polypropionate synthesis.
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