Part 9: SYNTHESIS

The schemes below give possible syntheses of the targets. There are of course other variations. The first part for each compound gives a "retro-synthesis", the "plan" and then the forward synthesis with reagents is given.  Red arrows try to show carbon-carbon bond forming reactions, blue arrows are functional group manipulations. The blue text rationalise the retrosynthetic analysis and information about important reactions are given in green.



IMAGES WILL BE ADDED AS TIME ALLOWS
LAST UPDATE APRIL 26th 2009


amide




Need to make benzaldehyde from benzene.... Bromobenzene (see above) + Mg / THF, add methanal to get benzyl alcohol then do a PCC or PDC oxidation.


An ester, so make the phenol and the acid is C2 so it's allowed.


A diester from a dicarboxylic acid via the ozonolysis of a Diels-Alder product

1,3-cyclopentadiene + ethene. Then react with O3 with oxidative work-up i.e. H2O2. Convert this dicarboxylic acid to the diester by heating with EtOH / H+.

A cyclic acetal from 1,2-ethanediol and cyclohexanone.

Cyclohexanone is made from cyclohexene by reacting it with H3O+ then oxidising (PCC or PDC or chromic acid or dichromate) to the ketone.
Cyclohexanone + HOCH2CH2OH + H+ and heat gives this product.

1-phenylcyclohexyl bromide via 1-phenylcyclohexanol....
Bromobenzene (see above) + Mg /THF, then add cyclohexanone (see above). This will give a tertiary alcohol, 1-phenylcyclohexanol. Treat this with HBr to give the desired product, 1-phenylcyclohexyl bromide.


via epoxide

Make the cyclopropane via a Simmons-Smith reaction on 2-phenylpropene.