A new total synthesis of (±)pisiferic acid†

Tetrahedron, 2002

A stereocontrolled approach to the construction of the angularly ester substituted trans-octahydrophenanthrene ring system related to diterpenes involving an aryl participated diazoketone cyclisation strategy is delineated. The tetrahydrophenanthrenone 7 was ...

European Journal of Organic Chemistry, 2015

Alkylation of the lithium enolate of (2S,3S,5S,6S)-dimethoxy-2,3-dimethyl-1,4-dioxane-5,6-dithiocarboxylate using 4benzyloxybenzyl bromide stereoselectively gave two new stereogenic centres with the carboxylate groups in a cis relationship. Hydrolytic deprotection of this intermediate pro-[a]

ChemInform, 1988

γ‐Methyl (S)‐glutamate (I) is protected to give the tritylamino derivative (III) which is transformed into the aminohydroxypentanoic acids (V) and (IX) mentioned in the title.

ChemInform, 2010

A simple and versatile procedure of pivalaldehyde synthesis is described. The synthesis is based on the formylation of tert-butyl magnesium chloride with excess of DMF in low temperature and can be easily performed in bulk scale. The application of DMF for the formylation of tertiary Grignard compounds is briefly discussed in terms of steric effects. interest. Up to now, however, no useful laboratory procedure of its synthesis has been reported. Aldehyde 1 used to be prepared by formylation of tert-butylmagnesium chloride (2) with methyl formate, ' ethyl formate,' N-methylf~rmanilide~ and N, N-dimethylformamide (DMF). 'a'4 Some other, generally less convenient methods were also applied. The use of DMF in the formylation of organometallic compounds (either Grignard or organolithium) was abandoned for a long time, probably due to the discouraging report of Bouveault,la which claimed a very poor yield of 1. Other attempts4 to apply DMF for the formylation of 2 were generally unsuccessful. Recently, some inviting papers5 appeared concerning the Bouveault synthesis of aldehydes, using N-formylalkylamines including DMF. 6 However, only one tertiary organolithium compound has been Since large amounts of title compound were required ,in our investigations on sterically crowded systems we decided to try to optimize the conditions of the Bouveault synthesis of 1 with DMF as formylating agent observing the recently published data. This work is to present the resulting useful, highly-efficient synthetic procedure.

Journal für praktische Chemie, 2000

The contribution of β-ketoesters to heterocyclic synthesis is well documented. Not only such established reactions as the Hantzsch pyridine [1] and pyrrole [2] syntheses and the Knorr pyrrole [3] and quinoline [4] syntheses require β-ketoesters, there are also many other examples in which they are applied to the preparation of new five-[5], six-[6] and seven-membered [7] heterocyclic ring systems. However, esters of 2-acetylsuccinic acid have rarely been used for this purpose; only very few syntheses of carboxylated pyrrolinone [8], furanone [9], thiophene [10] or isoxazole [11] derivatives have been described. Dimethyl acetylsuccinate is a commercially available compound, which was previously used mainly for the synthesis of cyclobutyl ketones or monoterpenoidal cyclohexenones . In this paper, we present its multifold possibilities in the construction of heterocyclic acetic acid derivatives.

Journal of Organic Chemistry, 1962

SOTES 4633 6a-p-nitrobenzamido-3a,5a-cycloandrostan-17-one, m .p.

Organic & Biomolecular Chemistry, 2012

General synthetic methodology for preparation of 9 S2 Ethyl 7-acetyl-8-oxononanoate (S1) S2 Ethyl-8-hydroxy-7-(1-hydroxyethyl)nonanoate (S2) S3 8-Hydroxy-7-(1-hydroxyethyl)nonanoic acid (9) S3 8-((Trimethylsilyl)oxy)-7-(1-((trimethylsilyl)oxy)ethyl)nonanoic acid (S3) S4 General synthetic methodology for preparation of 10 S4 2-(Prop-2-yn-1-yl)propane-1,3-diol (10) S4 2,2,8,8-Tetramethyl-5-(prop-2-yn-1-yl)-3,7-dioxa-2,8-disilanonane (S4) S5 Synthesis of 2-azidoacetic acid S5 References S5 ES + MS Spectrum of compound 15 S6 ES + MS spectrum of Biotin-Teg-FQQQTG-8 (16) S7 ES + MS Spectrum of compound 19 S8 ES + MS Spectrum of Biotin-Teg-YQEQTG-8 (20) S9 ES + MS Spectrum of compound 22 S10

The Journal of Organic Chemistry, 1962

SOTES 4633 6a-p-nitrobenzamido-3a,5a-cycloandrostan-17-one, m .p.

Tetrahedron, 1997

Cmhined use oJchemcn1 und enzymatic merhodsfor a short access to the JullyJunctionali:ed B-ring. the 2: I'. &I, 4u-ietmsub.Ftituted cyclohexene unit, ofA-seco mevinic acids is presented.

"A simple and versatile procedure of pivalaldehyde synthesis is described. The synthesis is based on the formylation of tert-butyl magnesium chloride with excess of DMF in low temperature and can be easily performed in bulk scale. The application of DMF for the formylation of tertiary Grignard compounds is briefly discussed in terms of steric effects".