Aldol condensation

We wish to report here our initial efforts toward the total synthesis of the potent antitumor agent dictyostatin, describing a short and efficient synthesis of the C11–C23 fragment. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Up to now, the anti-inflammatory agent nabumetone has been synthesized by a two-step process involving either a Heck reaction between 6-bromo-2-methoxynaphthalene and methyl vinyl ketone or a condensation between 6-methoxy-2 naphthaldehyde and acetone to give an intermediate that is separated, purified, and hydrogenated in a second and separate process to give the final product, while producing a large amount of

Catalytic C−C coupling and deoxygenation
reactions are essential for upgrading of biomass-derived
oxygenates to fuel-range hydrocarbons. Detailed understanding
of mechanistic and energetic aspects of these reactions is crucial
to enabling and improving the catalytic upgrading of small
oxygenates to useful chemicals and fuels. Using periodic density
functional theory (DFT) calculations, we have investigated the
reactions of furan and acetaldehyde in an HZSM-5 zeolite
catalyst, a representative system associated with the catalytic
upgrading of pyrolysis vapors. Comprehensive energy profiles
were computed for self-reactions (i.e., acetaldehyde coupling and
furan coupling) and cross-reactions (i.e., acetaldehyde + furan)
of this representative mixture. Major products proposed from the computations are further confirmed using temperature
controlled mass spectra measurements. The computational results show that furan interacts with acetaldehyde in HZSM-5 via an
alkylation mechanism, which is more favorable than the self-reactions, indicating that mixing furans with aldehydes could be a
promising approach to maximize effective C−C coupling and dehydration while reducing the catalyst deactivation (e.g., coke
formation) from aldehyde condensation.

A stereoselective total synthesis of rhoiptelol B has been accomplished for the first time. The four asymmetric centers were efficiently generated through Keck allylation, Jacobson epoxidation Aldol reaction and reductive etherification as the key steps.

Use water as solvent for the organic synthesis a great choice because it is economical, reduces waste and avoids potentially hazardous reagents versus the conventional solvents. This account presents the Cu(II)-b-CD as water soluble green catalyst for the one-pot conversion benzyl halide to benzyl azide and 1,2,3-trizoles at room temperature and very short reaction time (15-70 min). Products are separated without any workup, simple by filtration, with > 99 % selectivity and purity. As-synthesized material was characterized by, HR-TEM, XPS, FESEM, FT-IR, TGA and XRD to understand its structural properties as well as attachment of copper by host-guest interaction. This catalyst can also show effectiveness for the condensed ketone and aldehydes moiety, which produce biofuels intermediate. The recyclability of this catalytic system was tested up to five cycles and only a very slight loss of catalytic activity was detected.

The synthesis of the chiral core structure of the lissoclimide class of anti-tumour agents containing three rings, including a chiral succinimide subunit and an exocyclic double bond, has been investigated. The compound 7 was obtained, without the use of any protecting groups for the alcohol at C-12, via an asymmetric boron-mediated aldol addition as the key step to install the chiral centres of the rare succinimido methanol moiety. This was followed by a sequence of lactonisation, microwave-assisted amidation and imidation reactions.

In this paper, we report the crossed aldol condensation between the acetone and the 2,5-bis(octyloxy)-terephthalaldehyde (OTP) to obtain new photoluminescent oligomers as potential candidates for the construction of organic luminescent diodes (OLED's). The reaction is ...

Unexpected dimers of some 2-substituted indan-1-one derivatives were isolated during aldol condensation of indan-1-one with various aldehydes in the presence of KOH (see Scheme). Monomeric products, usually expected from aldol condensation, further underwent a base-catalyzed nucleophilic addition reaction to their dimeric form in some cases. The structures of these dimers were characterized by using various spectral techniques and in one case, structural details were determined from a high-resolution crystallographic analysis.