129287-85-0Relevant academic research and scientific papers
Stereoselective diazoalkane cycloadditions to chiral 5-alkylidene-1,3- dioxan-4-ones and 3-benzylidene-β-lactones
Bartels, Annett,Jones, Peter G.,Liebscher, Juergen
, p. 1645 - 1654 (2007/10/03)
Stereoselective 1,3-dipolar cycloaddition of diazoalkanes to (E)-5- alkylidene-1,3-dioxan-4-ones 1 and the (Z)-isomers (Z)-I afforded spiropyrazolines 3 and 10, respectively. The optically active 2-benzylidene- 3-methyl-β-lactone (8) was synthesized from the corresponding 5-benzylidene- 1,3-dioxan-4-one 1f by hydrolysis and recyclization and added diazomethane with opposite stereodifferentiation. Photochemical elimination of nitrogen from spiropyrazolines 3 gave enantiomerically pure spirocyclopropanes 12 that could be further transformed to cyclopropanecarboxylic acids 13 and derivatives 14.
(E,R,R)-5-Alkylidene-2-tert-butyl-6-methyl-1,3-dioxan-4-ones: Preparation from (R)-3-Hydroxybutbutyric Acid, Cuprate Additions and Hydrolyses to 3-Hydroxycarboxylic Acids with Chiral Secondary Alkyl Substituents in the 2-Position
Amberg, Willi,Seebach, Dieter
, p. 2413 - 2428 (2007/10/02)
Li enolates of (R,R)-2-tert-Butyl-6-methyl-1,3-dioxan-4-one add to aliphatic or aromatic aldehydes with relative topicity Re,Re (2:1 to 10:1, 9 examples).The title compounds are obtained from these aldol adducts by dehydration through mesylates (5 example
