(R)-2-tert-Butyl-6-methyl-4H-1,3-dioxin-4-one

(R) [107289-20-3] C9H14O3 (MW 170.21) InChI = 1S/C9H14O3/c1-6-5-7(10)12-8(11-6)9(2,3)4/h5,8H,1-4H3/t8-/m1/s1 InChIKey = HWPXDBBVCANLFT-MRVPVSSYSA-N (S) [139973-88-9] InChI = 1S/C9H14O3/c1-6-5-7(10)12-8(11-6)9(2,3)4/h5,8H,1-4H3/t8-/m0/s1 InChIKey = HWPXDBBVCANLFT-QMMMGPOBSA-N (enantiopure derivative of acetoacetic acid,2-4 highly reactive Michael acceptor for CuI-doped Grignard and for Gilman reagents;2, 5 component for [2 + 2] photocycloadditions;2 catalytic hydrogenation leads to the cis-disubstituted dioxanone;2, 5 the dienolate generated from the reagent can be used for chain elongations at the C(6)-Me carbon6) Physical Data mp 59.8–60.2 °C; [α]rtD = −215° (c = 1, CHCl3). Solubility sol most common organic solvents; poorly sol pentane at low temperature. Preparative Methods acid-catalyzed acetalization of Pivalaldehyde with (R)-3-hydroxybutanoic acid8 gives the cis-1,3-dioxan-4-one 1 in 40% yield after recrystallization from ether/pentane. (Up to 60% yield can be obtained by using freshly loaded acidic ion-exchange resin and following the procedure of Seebach et al.7b Runs with up to 120 g hydroxy butanoic acid were performed in this way). Bromination with N‐Bromosuccinimide leads to a mixture of brominated dioxinones which are debrominated hydrogenolytically to 1 (eq 1). The yield 2 → 1 is ∼45% after recrystallization from pentane/ether (50∶3) at −20 °C.4, 7 The enantiomer ent-1 is of course equally readily available from (S)-3-hydroxybutanoic acid.9 Both enantiomers of 3-hydroxybutanoic acid are commercially available. (1) Handling, Storage, and Precautions dioxinone 1 is commercially available and is indefinitely stable as a crystalline solid stored in a dark bottle at rt.