A new asymmetric synthesis of (S)-dolaphenine and its heteroaromatic congeners utilizing (+)-2-hydroxy-3-pinanone and (-)-3-hydroxy-2-caranone as chiral auxiliaries

Article abstract of DOI:10.1016/0040-4020(95)00828-V

(+)-2-hydroxy-3-pinanone ((+)-HyPN,(+)-2a) and (-)-3-hydroxy-2-caranone ((-)-2b) were respectively converted to the corresponding Schiff bases 18a and 18b with 1-(2-thiazolyl)methylamine (17). Alkylation followed by removal of the chiral auxiliaries (+)-2a and (-)-2b afforded (S)-dolaphenine (10) as an optically pure form. The method was applied to the asymmetric synthesis of the dolaphenine analogs 27a-d.