Sumários

Practical class

12 Outubro 2016, 16:00 • Christopher David Maycock

Continuation of Block 1 experiments (see previous summary)

Completion of synthesis of Hirsutene and Capnellene

12 Outubro 2016, 14:00 • Christopher David Maycock

Formation of alcohols by reduction of carboxylic acids. Activation of primary and secondary hydroxyl groups to nucleophilic attack using sulphonate esters. Formation of halides (iodides) by nucleophilic substitution. Use of alkynes and acetylene derivatives for the formation of C-C bonds. Ease of formation of carbanions from terminal alkynes (acidity). Reactivity of neopentyl groups. Generation of free radicals and their chain reactions.

Use of AIBN/heat as initiator and tin reagents as propagators. Tandem radical reactions and the formation of Hirsutene. Reduction of organic halides using tin reagents.
Capnellene a similar structure. SN2' strategy for the formation of quaternary centre with correct relative stereochemistry. Bayer-Villager rearrangement for the transformation of cyclic ketones into lactones. Acid catalysed (carbocationic) rearrangement of strained systems to form bicyclic lactones. Stereoselective SN2' reactions revisited. Iodolactonisation.

Presentation and Photolytic synthesis

28 Setembro 2016, 16:00 • Christopher David Maycock

Presentation of rules for the lab course. Use of lab-coat, Eye protection and general attention to safety in the laboratory. Formation of groups and start of the photolytic synthesis of benzopinacol using sunlight. Each student has a lab book. Experiment list:

Bloco 1

 

1. Sintese de Benzopinacol                                          Vogel P. 528 (method A) (1 aula)

 

2. Sintese de 7,7-Diclorobiciclo[4.1.0]heptano            Vogel P. 1110 (1 aula)

 

3. Sintese de 1,1’-Bi-2-naftol                                      Vogel P. 838 (1 aula)

 

4. Sintese de Ciclohexeno                                           Vogel P.491 (1 aula)

 

Bloco 2

 

5. ver folha      Sintese de 2-Amino-5-iodopiridina

 

6.ver folha       Sintese de 2-Cloro-5-iodopiridina

After experiment 1 the experiments will be rotated such that in the second lab, group 1 will do expt. 2, group 3 expt. 3, group 4 and 5 expt. 4. 

After finishing Block 1 all groups will do the block 2 experiments simultaneously.

Synthesis of Hirsutene by Curran

28 Setembro 2016, 14:00 • Christopher David Maycock

A synthesis of Hirsutene is described. Racemic synthesis with stereo control

Strategy based upon radical cyclisation.
Synthesis of radical precursor.
Selection of starting material.
1,2- or 1,4-addition in cyclopentenones. Use of Ce(III) reagents for selective 1.2 reduction. Formation of esters using activated carboxylic acids. Equilibrium and reaction conditions (reagents). Carbon acids and the use of strong non-nucleophilic bases (LDA). Formation of enolsilyl ethers and the chemistry of some silicon compounds. Cope rearrangement and the formation of C-C bonds. Selenolactonisation: stereochemistry and utility.
Oxidation of sulfur and selenium to sulfoxides and selenoxides. Pericyclic reaction of selenoxides and 2,3-sigmatropic rearrangements and the formation of double bonds. The THP protecting group. Formation of organolithium reagents by Br-Li exchange. Conversion to copper reagents and their use in 1,4-additions to nones and SN2' reactions.
 

Presentation

21 Setembro 2016, 16:00 • Christopher David Maycock

Recommended book Vogel.
Laboratory safety.
Experiment list.
Formation of 2 terms of about 10 students each.