102572-88-3Relevant academic research and scientific papers
HOMOCHIRAL KETALS IN ORGANIC SYNTHESIS. DIASTEREOSELECTIVE CYCLOPROPANATION OF α,β-UNSATURATED KETALS DERIVED FROM 1,4-Di-O-BENZYL-L-THREITOL
Mash, Eugene A.,Nelson, Keith A.
, p. 679 - 692 (2007/10/02)
2-Cykloalken-1-one 1,4-di-O-benzyl-L-threitol ketals undergo efficient and diastereoselective cyclopropanation when treated with an excess of the Simmons-Smith reagent.For example, 2-cyclohexen-1-one 1,4-di-O-benzyl-L-threitol ketal gave in 90-98percent yield a 9:1 mixture of diastereomeric cyclopropanes as established by 62.9 MHz 13C NMR spectroscopy and by hydrolysis of the mixture to (1R,6S)-bicycloheptan-2-one.Sixteen other examples are presented which demonstrate the generality and predictability of the process for 2-cycloalken-1-one ketals, as well as an unfortunate lack of diastereoselectivity for α,β-unsaturated 1,4-di-O-benzyl-L-threitol acetals.
Homochiral Ketals in Organic Synthesis. Enantioselective Synthesis of (R)-Muscone
Nelson, Keith A.,Mash, Eugene A.
, p. 2721 - 2724 (2007/10/02)
An efficient, enantioselective preparation of (R)-muscone employing a diastereoselective Simmons-Smith cyclopropanation is described.Cyclopropanation is directed via chelation control by a homochiral ketal protecting group derived from unnatural tartaric acid.The overall yield of (R)-muscone (>95percent R) from commercially available cyclopentadecanone is 60percent over seven steps.
