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 required 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.
Common general errors: (1) poor choice of reagents and / or conditions (2) incorrect starting materials (3) ignoring regio and / or stereoselectivity issues.