Diethyl -D-tartrate

L-diethyl tartrate (natural) [A] (-)-D-diethyl tartrate (unnatural) [B]... 

The Intermediate In this synthesis of disparlure, (Z)-2-tridecenol, Is obtained by hydrogenation of 2-trldecynol In the presence of a palladium catalyst poisoned with barium sulfate and quinoline. Oxidation of (Z)-2-tridecenol with tert-butyl hydroperoxlde/tItanium tetralsopropoxlde/D (-)-diethyl tartrate gives (2R, 3S)-epoxytrldecanol In enantiomeric excess reported to be as much as 98 percent after recrystalllzatlon. 

The SAE is arguably one of the most important reactions discovered in the last 30 years. The SAE converts the double bond of allyl alcohols into epoxides with high enantioselective purity using a titanium tetraisopropoxide catalyst, Ti(0-iPr)4, chiral additive, either L-(+)-diethyl tartrate [(+)-DET, 7.45] or D-(—)-diethyl tartrate [(—)-DET, 7.46], and tert-butyl peroxide (t-BuOOH, TBHP (f-butylhydroperoxide)) as the source of the oxidant in stoichiometric amounts (see section 1.5, references 28-30 of Chapter 1). 

D-(-)-diethyl tartrate delivers oxygen to top face of alkene... 

An actual breakthrough in the field of asymmetric epoxidation was the discovery of a new method for the preparation of homochiral epoxy alcohols by Katsuki and Sharpless in 1980 [13]. The main idea was to change the catalytic system and to use titanium tetraisopropoxide and l-( + )- or d-( — )-diethyl tartrate (DET). With water-free solutions of TBHP various allylic alcohols can be epoxidized with high enantioselectivity. 

Synthesis from o-threose Synthesis of DABl (1) has been carried out by conversion of the D-threose derivative 33, readily available from D-(—)-diethyl tartrate, to the aminonitrile 34 as an inseparable diastereomeric mixture (Scheme 7). Subsequent deprotection with TBAF gave the alcohol 35 (quantitative). Esterification of 35 with p-toluenesulfonyl chloride afforded 36 (84%), which was treated with TFA-H2O-THF... 

---