132747-06-9Relevant articles and documents
Application of radical cyclisation/iodine atom transfer to the chiral synthesis of (-)-methylenolactocin
Mawson, Simon D.,Weavers, Rex T.
, p. 11257 - 11270 (1995)
Methylenolactocin, an antitumour antibiotic, has been synthesized through an efficient radical cyclisation process on a chiral iodo acetylene ester. Chiral iodohydrins may be formed by regioselective opening of a chiral epoxy ester, prepared by Sharpless epoxidation. C-2 opening is achieved with TMSCl/NaI and C-3 attack with MgI2. Subsequent esterification of the 2-iodo compound by reaction with substituted propynoyl triflates gives the key iodo acetylenic esters. This route is highly adaptable to the synthesis of analogues.
A general stereospecific synthesis of γ-hydroxy-α,β-unsaturated esters
Thijs,Dommerholt,Leemhuis,Zwanenburg
, p. 6589 - 6592 (2007/10/02)
A stereospecific synthesis of optically active γ-hydroxy-α,β-unsaturated esters is achieved, involving successively the Sharpless epoxidation of allylic alcohols, oxidation to glycidic acids, conversion into α,β-epoxy diazomethyl ketones, and irradiation in ethanol at 300 nm. Intermediates in the photo-induced rearrangement are epoxy ketenes, which undergo ethanolysis with simultaneous opening of the epoxide, preferably via a transition state involving the s-trans conformation.
