Two chiral intermediates, C(1)–C(9) and C(11)–C(17) portionsof protomycinolide IV, were synthesized both from (S)-ethyl lactatevia asymmetric pinacol-type rearrangement followed bydiastereoselective reactions on α-methyl-β,γ-unsaturatedcarbonyl compounds.
Highly stereoselective approach to chiral building block possessing three contiguous asymmetric centers. Preparation of four possible diastereomers of β,β′-dimethyl-bis-homoallylic alcohol derivative