Synthesis of optically active chalcogran from L-sorbose

Article abstract of DOI:10.1016/0008-6215(94)84020-2

The synthesis of (2S,5RS)-2-ethyl-1,6-dioxaspiro[4,4]nonane (chalcogran) (1) from 2,3:4,6-di-O-isopropylidene-α-L-sorbofuranose (2) through elongation of the carbon chain at C-1 and C-6 by the Wittig and Corcy methodologies, respectively, spiroacetalation