title: Asymmetric synthesis of hexapropionate synthons by sequential enantiotopic group selective enolization of meso diketones.
abstract: Meso 1,9-diketones (six to seven stereocenters) are readily obtained by stepwise or simultaneous two-directional aldol reactions of tetrahydro-4H-thiopyran-4-one with a thiopyran-derived aldehyde or dialdehyde. Enantioselective enolizations of these diketones with the lithium amide from (R,R)-bis(1-phenylethyl)amine occur with simultaneous kinetic resolution to give the mono-TMS enol ethers in >90% yields (BORSM) and >95% ee. The products are applicable to polypropionate synthesis. [reaction: see text]
authors.affiliation: Department of Chemistry, University of Saskatchewan, Saskatoon, SK S7N 5C9, Canada. dale.ward@usask.ca
authors.forename: Dale E
authors.initials: DE
authors.lastname: Ward
authors.forename: H Martin
authors.initials: HM
authors.lastname: Gillis
authors.forename: Olukayode T
authors.initials: OT
authors.lastname: Akinnusi
authors.forename: M Abdul
authors.initials: MA
authors.lastname: Rasheed
authors.forename: K
authors.initials: K
authors.lastname: Saravanan
authors.forename: Pradip K
authors.initials: PK
authors.lastname: Sasmal