Photo-organocatalytic synthesis of acetals from aldehydes

Abstract

A mild and green photo-organocatalytic protocol for the highly efficient acetalization of aldehydes has been developed. Utilizing thioxanthenone as the photocatalyst and inexpensive household lamps as the light source, a variety of aromatic and aliphatic aldehydes have been converted into acyclic and cyclic acetals in high yields. The reaction mechanism was extensively studied

Photo-organocatalytic synthesis of acetals from aldehydes

 

Nikolaos F. Nikitas,^a  Ierasia Triandafillidi^a  and  Christoforos G. Kokotos*^a 

 Author affiliations

*Corresponding authors

^aLaboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15771, Greece
E-mail:ckokotos@chem.uoa.gr

https://pubs.rsc.org/en/Content/ArticleLanding/2019/GC/C8GC03605E?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

(3,3-Dimethoxypropyl)benzene (2a)6
Colorless oil; 95% yield; 1H NMR (200 MHz, CDCl3) δ: 7.33-7.18 (5H, m, ArH), 4.37 (1H, t, J = 5.8 Hz, OCH), 3.33 (6H, s, 2 x OCH3), 2.68 (2H, t, J = 7.6 Hz, CH2), 1.98- 1.87 (2H, m, CH2); 13C NMR (50 MHz, CDCl3) δ: 141.8, 128.4, 125.9, 103.7, 52.8, 34.0, 30.8; MS (ESI) m/z 181 [M+H]+ .
6. Q. Zhou, T. Jia. X.-X. Li, L. Zhou, C.-J. Li, Y. S. Feng, Synth. Commun., 2018, 48, 1068.

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Endo-4,7-bis(hydroxymethyl)hexahydro-1H-4,7-epoxyisoindole-1,3(2H)-dione (endo-4,7- bis(hydroxymethyl)norcantharimide)

Endo-4,7-bis(hydroxymethyl)hexahydro-1H-4,7-epoxyisoindole-1,3(2H)-dione (endo-4,7- bis(hydroxymethyl)norcantharimide), 4 (method A)

Endo-4,7-bis(hydroxymethyl)norcantharimid-5-ene (120 mg, 0.53 mmol) was dissolved in water (3 mL), Pd/C 10% was added (15 mg) and reaction mixture was placed under hydrogen atmosphere for 8 h at 24 °C. Catalyst was filtered off and washed thoroughly with water (3 × 3 mL), filtrate was evaporated under reduced pressure. Target compound 4 was obtained as white solid, yield 87% (110 mg).

1H NMR (D2O) = 3.76 (s, 4H), 3.46 (s, 2H), 1.61-1.72 (m, 4H);

1H NMR (DMSO-d6) = 11.10 (s, 1H), 5.08 (s, 2H), 3.66 (s, 4H), 3.37 (s, 2H), 1.71 (m, 2H), 1.49 (m, 2H);

13C NMR (D2O) = 179.0, 88.8, 60.7, 52.3, 27.0 ppm.

m/z HRMS (ESI) Calcd. for C10H13NO5 [M+Na]: 250.0686. Found 250.0696.

Efficient route for the construction of polycyclic systems from bioderived HMF 

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC02211E, Paper

F. A. Kucherov, K. I. Galkin, E. G. Gordeev, V. P. Ananikov
Efficient one-pot synthesis of tricyclic compounds from biobased 5-hydroxymethylfurfural (HMF) is described using a [4 + 2] cycloaddition reaction.

Efficient route for the construction of polycyclic systems from bioderived HMF

F. A. Kucherov,^a  K. I. Galkin,^a  E. G. Gordeev^a  and  V. P. Ananikov*^a 

 Author affiliations

*Corresponding authors

^aZelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky pr. 47, Moscow 119991, Russia
E-mail: val@ioc.ac.ru
Web: http://AnanikovLab.ru

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Oleanolic acid spectral data and interpretation

Oleanolic acid spectral data and interpretation

Oleanolic acid
(4aS,6aR,6aS,6bR,8aR,10S,12aR,14bS)-10-hydroxy-2,2,6a,6b,9,9,12a-heptamethyl-1,3,4,5,6,6a,7,8,8a,10,11,12,13,14b-tetradecahydropicene-4a-carboxylic acid

see full interpretation, 1H NMR, 13C NMR at

http://orgspectroscopyint.blogspot.in/2014/08/oleanolic-acid-spectral-data-and.html

Ethyl acetoacetate 乙酰乙酸乙酯 teaches you Organic spectroscopy... brush up?????

read at
http://orgspectroscopyint.blogspot.in/2014/04/ethyl-acetoacetate-teaches-you-organic.html

Ethyl 3-oxobutanoate
Acetoacetic acid ethyl ester
Ethyl acetylacetate
3-Oxobutanoic acid ethyl ester

Ethyl acetoacetate is produced industrially by treatment of diketene with ethanol.

The preparation of ethyl acetoacetate is a classic laboratory procedure.^[2] It is prepared via the Claisen condensation of ethyl acetate. Two moles of ethyl acetate condense to form one mole each of ethyl acetoacetate and ethanol.

Structure: 

IUPAC Name: ethyl 3-oxobutanoate (ethyl acetoacetate)

Analysis: C₆H₁₀O₃: MW = 130.14


The molecule contains an oxygen, and from the analysis, contains two double bonds, carbonyls or rings.
The mass spectrum displays a molecular ion and the base peak represents the formation of the acylium ion, indicating the presence of a methyl adjacent to a carbonyl. The presence of an m-45 peak strongly suggests the presence of an ethoxy group.
The ¹³C spectrum contains six peaks, indicating that all carbons are unique. The quartets at  14 and 24 represent relatively simple methyl groups; the triplets at  59 and 47 represent a CH₂ groups bonded to mildly electronegative groups; the singlets at  207 and 172 are in the carbonyl region, and most likely a ketone or aldehyde ( 207) and an ester ( 172).
The proton NMR shows evidence for an ethyl group and isolated CH₂ and CH₃ groups. The methylene of the ethyl group must be next to an electronegative atom (most likely oxygen) suggesting an -OCH₂CH₃ group. The isolated CH₂ must also be flanked by mildly electronegative groups, and the isolated CH₃ is in the region often observed for methyls adjacent to carbonyls.
The IR is consistent with a simple saturated hydrocarbon, possibly containing two carbonyls (based on the side peak at  1670 cm^-1). The minor peak at 3400 cm^-1 is too small to be an -OH.
The simplest structure which is consistent with all of these data would be a dicarbonyl compound containing an ethoxy residue and a methyl ketone (based on the presence of the acylium ion in the MS).
http://orgspectroscopyint.blogspot.in/2014/04/ethyl-acetoacetate-teaches-you-organic.html

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1H NMR

The proton NMR has a quartet coupled to a triplet, indicative of an ethyl group. The CH₂ must be adjacent to an electron withdrawing group since it is shifted to  4.1. The two singlets at  2.2 and 3.2 suggest isolated CH₂ and CH₃ groups and the CH₂ must be adjacent to one or more electronegative groups.

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http://orgspectroscopyint.blogspot.in/2014/04/ethyl-acetoacetate-teaches-you-organic.html
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13C NMR
¹³C NMR Assignments: 
¹³C NMR Data: q-13.6; q-24.2; t-59.2; t-46.6; s-172.0; s-207.1 
The ¹³C spectrum contains six peaks, indicating that all carbons are unique. The quartets at  14 and 24 represent relatively simple methyl groups; the triplets at  59 and 47 represent a CH₂ groups bonded to mildly electronegative groups; the singlets at  207 and 172 are in the carbonyl region, and most likely a ketone or aldehyde ( 207) and an ester ( 172).

ethyl acetoacetate CH3COCH2COOCH2CH3

http://orgspectroscopyint.blogspot.in/2014/04/ethyl-acetoacetate-teaches-you-organic.html

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MASS SPECTROSCOPY




Mass Spectrum Fragments: 
The mass spectrum consists of a molecular ion at 130, an m-15 peak at 115, which is consistent with loss of a CH₃ group, an m-43 peak (loss of acylium), an m-45 peak (loss of CH₃CH₂O-), and a base peak at m-43(m/e = 43) which suggests the formation of an acylium ion (CH₃-CO). The spectrum is consistent with a molecule which can lose methyl or ethoxy radicals, or can undergo fragmentation to form the acylium radical cation.


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IR

3400-3200 cm^-1: no OH peak (too small) 3100 cm^-1: no significant peak, suggesting no unsaturated CH 2900 cm^-1: strong peak suggesting saturated CH 2200 cm^-1: no unsymmetrical triple bonds 1710 cm^-1: strong carbonyl with a second peak at 1670 cm^-1, suggesting a the possibility of two carbonyls 1600 cm^-1: no significant peaks, suggesting no carbon-carbon double bonds




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2D [1H,1H]-TOCSY




1D DEPT135





2D [1H,13C]-HSQC



2D [1H,13C]-HMBC





2D [1H,1H]-COSY


2D [1H,13C]-HMQC

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