First Enantioselective Synthesis of (-)-(2S,6S)-(6-Ethyltetrahydropyran-2-yl)formic Acid

• DOI: 10.1055/s-2005-863744
• Publication Date: 2005-03-10T09:11:06Z
• Authors: Mário L. Vasconce...; Leandro S. M. Mir...; Bruno A. Meireles; Jerônimo S. Costa; Vera. L. Pereira
• Keywords: Stereocenter; Aqueous medium

We describe in this letter the first enantioselective synthesis of (-)-(2S,6S)-(6-ethyltetrahydropyran-2-yl)formic acid (2) five steps (30% overall yield, 87% ee), from commercial chiral template (R)-2,3-isopropylideneglyceraldehyde (4). The two stereogenic centers 2 were controlled by diastereoselective ­Barbier allylation 4 aqueous media and an efficient Prins ­cyclization reaction between 5 with propanal.