Answers to the synthesis problems are given below.  These answers have been selected as they are short and efficient, but there are probably other reasonable solutions.  Note some targets have specific stereochemistry that needs to be considered.

When planning syntheses, one should try to work backwards by functional group analysis. The diagrams show the "retrosynthesis" - the design or plan and then below that the reaction scheme step-by-step (as required in the question). 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 errors: trying to use a Friedel-Crafts acylation (that's a reaction of aromatic systems)

Common errors: poor choice of dienophile (better with electron withdrawing groups), missing C=C in the Diels-Alder product, wrong combinations of diene and dienophile

Common errors: trying to use Diels-Alder or aldol type chemistry (which are less effective given the allowed starting materials), incorrect reagents for alcohol dehydration and radical halogenation

Common errors: incorrect stereochemistry, using several steps to add the Cl (e.g. going via OH), confusing NaNH₂ and Na/NH₃

Common errors: trying to do Friedel-Crafts reactions on a deactivated system, ignoring directing effects

Common errors: showing that aldehydes react with two equivalents of Grignard reagents, wrong reagents for halogenating benzene

General comments.... Some students started from hydrocarbons with 3 C or less and then made errors in making the materials they could have just used as starting materials.

Common errors included:

(1) incorrect counting of C atoms
(2) trying Freidel-Crafts reactions on deactivated systems or with vinyl halides or ignoring rearrangements in alkylations
(3) trying to use Friedel-Crafts to make benzaldehyde (it can only be used to give aromatic ketones)
(4) trying to do Grignard reactions in the presence of acidic H atoms (e.g. -OH / -NH or CO₂H groups)
(5) trying to use Grignard reactions of RMgX with R-X (these tend to fail due to elimination or Mg exchange)
(6) wrong reagents for transformations e.g. strong base to eliminate alcohols instead of acid.
(7) confusing NaNH₂ and Na / NH₃
(8) poor management / control / incorrect regio and/or stereochemistry

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