STEREOSELECTIVE SYNTHESES OF (+)- ISORETRONECANOL AND (+)-5-epi-TASHIROMINE VIA ADDITION OF CHIRAL TITANIUM (IV) ENOLATES TO CYCLIC N-ACYLIMINIUM IONS
نویسندگان
چکیده
The stereoselective addition of the titanium (IV) enolates derived from (S)-4-isopropyl-N-4-chlorobutyryl-1,3-thiazolidine-2-thione (8) and from (S)-4-isopropyl-N-4-chloropentanoyl-1,3-thiazolidine-2-thione (9) to N-Boc-2-methoxypyrrolidine (5b) afforded the addition products (+)-10 and (+)-11 in 84% yield in both cases, as 8.6:1 and 10:1 diastereoisomeric mixtures, respectively. A threestep sequence allowed to convert these adducts to (+)-isoretronecanol (1) and (+)-5-epi-tashiromine (2) in 43% and 49% overall yield, respectively.
منابع مشابه
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