𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Enantioselective synthesis of α-sulfenylated ketones and aldehydes via α-thiolation of metalated SAMP/RAMP hydrazones

✍ Scribed by Dieter Enders; Thomas Schäfer; Wolfgang Mies

Publisher
Elsevier Science
Year
1998
Tongue
French
Weight
776 KB
Volume
54
Category
Article
ISSN
0040-4020

No coin nor oath required. For personal study only.

✦ Synopsis

Asymmetric ot-sulfenylation of lithiated SAMP/RAMP hydrazoncs (3")-2 with disulfides afforded tz-thiolated hydrazones (S,R)-3 in good yields (48-87%) and high diastcreomeric excesses (91-96%). Subsequent oxidative cleavage or acidic hydrolysis of the hydrazones furnished a-thiolated ketones (R)-4a.d with high enantiomeric excesses (87->96%). ct-Sulfenylated aldehydes (R)-Sa-d were prepared by a similar reaction sequence with 45-93% ee.

📜 SIMILAR VOLUMES

Enantioselective synthesis of protected
Enantioselective synthesis of protected α-hydroxy aldehydes and ketones via hydroxylation of metalated chiral hydrazones
✍ Dieter Enders; Vidya Bhushan 📂 Article 📅 1988 🏛 Elsevier Science 🌐 French ⚖ 282 KB

a-Benzyloxy aldehydes and a-acetoxy ketones 4 of high enantiomeric purity are prepared in good overall yields via oxaziridine mediated hydroxylation of chiral hydrazone azaenolates. As auxiliaries novel proline derived hydrazine reagents 5 are used. The importance of a-hydroxy carbonyl compounds as

Asymmetric michael additions via SAMP/RA
Asymmetric michael additions via SAMP/RAMP hydrazones enantioselective synthesis of 2-substituted 4-oxophosphonates
✍ Enders, Dieter ;Wahl, Heiner ;Papadopoulos, Kyriakos 📂 Article 📅 1995 🏛 John Wiley and Sons 🌐 English ⚖ 979 KB

## Abstract Asymmetric Michael addition of lithiated methyl ketone SAMP hydrazones (S)‐3 to a variety of alkenylphosphonates (E)‐2 followed by oxidative cleavage of the 1,4‐adducts (__S,S__)‐4 by ozonolysis afforded 2‐substituted 4‐oxophosphonates (__S__)‐5 in usually moderate to very good overall