[17639-76-8] · C5H10O3 · Methyl O-Methyllactate · (MW 118.15)
(lithium enolate used in the stereoselective synthesis of 2-methoxy-3-hydroxypropionate derivatives3)
Physical Data: bp 130-131 °C.
The (Z)-lithium enolate (2), derived from reaction of methyl O-methyllactate (1) with Lithium Diisopropylamide, reacts with aldehydes to form (3) (l isomer) in preference to (4) (u isomer) (eq 1).3 The stereoselectivity is approximately 3:1 in reactions with straight-chain and aromatic aldehydes. Stereospecificity is achieved in reactions with aldehydes with branching at the a-carbon. Other ethers (e.g. benzyl or MEM) derived from methyl lactate exhibit the same trend in stereoselectivity, although the magnitude is lower.3 Stereoselectivity in favor of compounds of u relative stereochemistry, illustrated in (4), is obtained in reactions using the benzyl ether derivative of a hindered ester (e.g. 5).3 The stereoselectivity in aldol reactions of (2) has been used to set the relative stereochemistry at C-3 and C-4 in a synthesis of
William A. Kleschick DowElanco, Indianapolis, IN, USA
William A. Kleschick
DowElanco, Indianapolis, IN, USA