title: Stereoselective total synthesis of dinemasone A by double intramolecular hetero-Michael addition (DIHMA).
abstract: The first total synthesis of dinemasone A, a bioactive metabolite with a spiroketal moiety, is described. The main strategy for the construction of the spiroketal unit involves a double intramolecular hetero-Michael addition (DIHMA) of an ynone moiety. The thus obtained axial-equatorial mono anomeric spiroketal, on spiroepimerization with ZnBr(2), was converted into the requisite axial-axial double anomeric spiroketal. The ynone moiety with four stereocentres, was prepared from a chiral propargylic alcohol (C5-C11 fragment) and a dihydroxy aldehyde (C1-C4 fragment), which in turn were obtained from D-mannitol and crotyl alcohol respectively.
authors.affiliation: Organic and Biomolecular Chemistry Division, Hyderabad-500 007, India. esmvee@iict.res.in
authors.forename: Gangavaram V M
authors.initials: GV
authors.lastname: Sharma
authors.forename: Gourishetty
authors.initials: G
authors.lastname: Srikanth
authors.forename: Pothula Purushotham
authors.initials: PP
authors.lastname: Reddy
mesh_terms: D000440:Butanols / Q000737:chemistry; D008353:Mannitol / Q000031:analogs & derivatives / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000440:Butanols; D011753:Pyrones; D013141:Spiro Compounds; C578835:dinemasone A; D008353:Mannitol; C007153:crotonyl alcohol