Homoallenyl boronate

Brown and co-workers developed a novel homoallenyl boronate reagent 169 based on diisopropyl tartrate for the stereoselective homoallenylation of aldehydes 170. The reagent 169 was prepared via homologation of the corresponding allenyl boronate or the alkylation of halomethyl boronate with allenyl Grignard similar to those reported in Scheme 26. The allyl boronate 169 upon reaction with aldehydes furnished the dienyl alcohols 172 with high ee (Scheme 28) <1996JOC100>. 

E.A. Theodorakis and co-workers reported the total synthesis of clerocidin, a diterpenoid antibiotic. To form the C12 stereocenter and the diene moiety, they applied an asymmetric homoallenylboration method. The reaction of the aldehyde and (S,S)-diisopropyltartrate-derived homoallenyl boronate provided the alcohol with a 6 1 diastereoselectivity and 83% yield. 

---

See also in sourсe #XX -- [ ]

---