72284-17-4

Upstream product

• 111-71-7 heptanal 
• 52790-15-5 O-Ethyl S-ethoxycarbonylmethyl thiocarbonate 
• 623-51-8 ethyl 2-sulfanylacetate 
• 1099-45-2 ethyl (triphenylphosphoranylidene)acetate 
• 867-13-0 diethoxyphosphoryl-acetic acid ethyl ester 
• 3761-92-0 n-hexylmagnesium bromide 
• 623-47-2 propynoic acid ethyl ester 
• 1071-46-1 hydrogen ethyl malonate 
• 311-46-6 ethyl 2-(dimethoxyphosphoryl)acetate 

Relevant academic research and scientific papers

A highly stereoselective TMSOTf-mediated catalytic carbocupration of alkynoates

(Chemical Equation Presented) The TMSOTf-mediated catalytic carbocupration of ynoates has been investigated. It has been shown that catalyst loadings as low as 5 mol % readily allow for high yields and diastereosetectivities for a series of aromatic Grignard reagents. In addition, we have been successful in vicinally functionalizing 1a via initial TMSOTf-mediated catalytic carbocupration followed by a secondary electrophilic capture of the TMS allenoate intermediate.

Practical synthesis of (E)-α,β-unsaturated esters from aldehydes

Based on a modification of the Doebner-Knoevenagel reaction, a practical and highly efficient synthesis of β,β-unsaturated esters with excellent regio- and stereoselectivity was developed. The reactions are catalyzed by 4-dimethylaminopyridine in DMF at room temperature or below. Both aliphatic and aromatic aldehydes can readily be used in the process.

Stereocontrol of the Horner-Wadsworth-Emmons Reaction: Application to the Synthesis of HIV-1 Protease Inhibitors

A systematic study on the Horner-Wadsworth-Emmons (HWE) reaction has shown that ethyl diphenylphosphonoacetate and methyl diphenylphosphonoacetate give a high excess of (Z)-alkenes. These reaction conditions were then used to prepare (Z)-ethyl-5-phenylpent-2-enoate, the corresponding (E)-isomer being prepared by standard Wittig chemistry. Reduction of each allylic ester, with diisobutylaluminium hydride (DIBAL), gave the allylic alcohols (15) and (19), respectively. Epoxidation of (15) and (19), under Sharpless conditions, gave separate samples of all four stereoisomers of 2,3-epoxy-5-phenylpentan-1-ol. Esterification of each isomer with Cbz-valine, under Mitsunobu conditions, provided (9)-(12) which were assayed against HIV protease. The cis series (9)-(10) proved to be significantly more potent than the trans (11)-12) and, within each of these series, the isomers derived from L-diisopropyltartrate [(9) and (11)] were the most active.

Activated Alumina Promoted Stereoselective Wittig Reaction

Aldehydes undergo efficient E-stereoselective Wittig olefination with alkylidenetriphenylphosphoranes in the presence of activated alumina under mild conditions with high yields.

1,3-Dimethyl 2-oxo 1,3,2-diazaphospholidine precursor of (Z) α,β-unsaturated esters

α,β-Unsaturated esters of (Z) geometry are selectively obtained from cyclic phosphonocarboxylates derived from N,N'-dimethylethylenediamine.