Diisopropyl malate

The best compromise with respect to reactivity and availability of the starting material was the use of diisopropyl malate 107. This malic acid ester is easy to prepare and its alkylation with various benzyl bromides can be achieved with good yields (53-67%, not optimized) and high stereoselectivities (dr 95 5 for 120 and 121). An exception with respect to the stereoselectivity was the 2,4,6-trimethylbenzyl substituted succinate 122, which was obtained in a dr of only 83 17 (Fig. 6) [71]. 

Hydrogenolysis of the benzylether of lactone 141 (H2, 10% Pd/C) quantitatively afforded (-)-wikstromol ent-3). The overall yield of ent-3 from diisopropyl malate 107 over six steps was 30% [62]. This strategy for the construction of optically-active lactone lignans provided a short and stereoselective synthesis with comparably good overall yield. 

Reactions with nucleophiles. Many of these reactions have been carried out with cyclic sulfate 1, available in 90-93% yield from diisopropyl (+ )-tartrate. This sulfate is reduced at pH 4-5 by sodium cyanoborohydride in THF to diisopropyl (R)-malate in 55% (equation II). 

The vicinal diol cyclic sulfate from dimethyl tartrate undergoes nucleophilic opening to give substituted malate esters., However, for this application diethyl and diisopropyl L-tartrates give superior yields and selectivities. The asymmetric cyclopropana-tion of the 1 -alkenylboronic ester derived from dimethyl L-tartrate (eq 5) is another example where other tartaric acid derivatives surpass the performance of dimethyl tartrate. ... 

Alkylation of diisopropyl (7 )-malate with benzyl bromide produces a 10 1 mixture of benzylated product 945 in 80—85% yield. Use of the isopropyl ester results in higher yields than in the case of the corresponding methyl or ethyl esters, presumably due to reduced ester— enolate condensation. Purification of the diastereomeric mixture is accomplished by hydrolysis to diacid 946 and recrystallization from either chloroform or ethyl acetate/hexane [52% overall yield from diisopropyl (i )-malate]. Treatment of 946 with acetyl chloride and subsequent reaction with isopropyl alcohol gives monoester 948 in 95% overall yield. Amidation of the free acid followed by Hofmann degradation affords 950 in 90% overall yield. Removal of the Boc group and hydrogenation of the benzene ring provides 952. 

The key aldehyde 1151 is prepared from the malic acid-derived tosylate 59 as illustrated in Scheme 168. Attempted displacement of the tosyl function of 1145 with carbon nucleophiles fails due to base sensitivity caused by the ester group. Consequently, the ester is instead converted to a diisopropyl acetal, which alleviates the problem. Nucleophilic displacement of the tosylate with cyanide proceeds cleanly in this case to give nitrile 1147. Conversion of the nitrile to aldehyde 1148 followed by Wittig reaction with 1149 produces the protected (Z,Z)-diene 1150 with >95% (Z)-stereoselectivity. Hydrolysis of the acetal gives the dienal 1151 in 21% overall yield from dimethyl (5)-malate. 

Estabex 138-A, Estabex 2307 DEOD, Estabex 2307. See Epoxidized soybean oil, Estabex 2381. See 2-Ethylhexyl epoxystearate, Estaflex ATC. See Acetyl tributyl citrate Estalan 12. See Laureth-2 octanoate Estalan 38, Estalan 42. See Laureth-2 acetate Estalan 126. See Laureth-2 benzoate Estalan 430. See Diethylene glycol dioctanoate/diisononanoate Estalan 718. See Octyl hydroxystearate Estalan 816. See Octyl palmitate Estalan CM. See Cetyl myristate Estalan CP. See Cetyl palmitate Estalan CSO. See Cetearyl octanoate Estalan DIA. See Diisopropyl adipate Estalan-DID. See Diisopropyl dimer dilinoleate Estalan-DIPS. See Diisopropyl sebacate Estalan DISD. See Diisostearyl dimer dilinoleate Estalan-DISM. See Diisostearyl malate Estalan DNPA. See Dipropyl adipate Estalan DO. See Decyl oleate Estalan DOM, Estalan-DOMA. See Dioctyl maleate... 

Dihydrolanosterol Dihydrophytosteryl octyidecanoate Dihydroxyethylamino hydroxypropyl oleate Dihydroxyethyl soyamine dioleate Diisobutyl adipate Diisocetyl adipate Diisononyl adipate Diisopropyl adipate Diisopropyl dimer dilinoleate Diisostearyl adipate Diisostearyl dimer dilinoleate Diisostearyl glutarate Diisostearyl malate Dilaureth-7 citrate Dilauryl citrate Dimethicone Dimethicone copolyol Dimethicone copolyol acetate Dimethicone... 

Behenyl isostearate Caprylyl methicone Cetearyl behenate Cetearyl candelillate Cholesteryl/behenyl/octyidodecyl lauroyl glutamate Diisopropyl dimer dilinoleate Diisostearyl malate Hexyldecyl benzoate Isostearyl stearoyl stearate Macadamia ternifolia nut oil Methyl stearoxy dimethicone Myristoyl hydrolyzed collagen Myristyl myristate... 

Beeswax, white Beeswax, yellow Benzoic, acid Benzyl tiglate y-Bisabolene Brominated vegetable oil 3-Butylidenephthalide Butyloxepanone 3-Butylphthalide Calcium lactate Caramel Castor (Ricinus communis) oil Citronellyl isovalerate Citronellyloxy acetaldehyde p-Cresyl isovalerate p-Cresyl octanoate Crotonic acid p-Cyclocitral p-Damascenone 9-Decenal trans-4-Decenal Diacetyl tartaric acid esters of mono- and diglycerides Diethyl malate Difurfuryl disulfide Dihydroeugenol Dihydro-a-ionone Dihydrojasmone Diisobutyl ketone Diisopropyl disulfide 3,4-Dimethylcyclopentane-1,2-dione Dimethyl dicarbonate 2,5 Dimethyl-3-furanthiol p-a-Dimethylstyrene Diphenyl oxide Ethyl acetate... 

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