Synthesis of enantiomerically pure 24-alkylsterol side chains, in both enantiomeric forms, starting from (R)-(+)-limonene

Three couples of enantiomeric synthons corresponding to six 24-alkylsterol side chains, (R)- and (S)-1-bromo-3,4-dimethylpentane, (R)- and (S)-1-bromo-3-ethyl-4-methylpentane, and (R)- and (S)-5-(acetyloxy)-1-bromo-3-(1-methylethyl)pentane, were synthesized from the same chiral intermediate, (R)-5-(acyloxy)-3-(1-methylethyl)pentan-1-ol, readily obtainable from (R)-(+)-limonene.