Octanal → HCID 11378750, compound

Participants

Reaction Steps

To a flame dried flask under a N2 atmosphere was added 5.0 g of 4 Å molecular sieves and 100 mL of anhydrous CH2Cl2, followed by 1.9 g (7.8 mmol) of TiCl2(i-PrO)2 and 2.2 g (7.8 mmol) of (R)-(+)-1,1′-bi-2-naphthol. The solution immediately turned red and was stirred at room temperature for 2 h. To this solution was added 17.9 mL (58.3 mmol) of allyltributyltin. The reaction was cooled to −20° C. and 5.0 g (39.0 mmol) of octanal was added. The solution was allowed to stir for 48 h at −20° C. The solution was filtered through a plug of Celite and the solvent was removed under reduced pressure. The remaining residue was purified by flash chromatography eluting with 1:9 EtOAc-hexanes to give 2.5 g (38%) of allylic alcohol 27. 1H NMR (400 MHz, CDCl3) δ 5.85-5.75 (m, 1H), 5.11-5.07 (m, 2H), 3.60 (m, 1H), 2.29-2.22 (m, 1H), 2.14-2.07 (m, 1H), 1.91 (br s, 1H), 1.44-1.41 (m, 2H), 1.32-1.22 (m, 10H), 0.85 (t, J=6.5 Hz, 3H); 13C NMR (400 MHz, CDCl3) δ 133.6, 116.8, 70.8, 42.6, 37.6, 32.8, 30.6, 30.3, 26.7, 23.8, 15.4. [α]23 (c 1.04, CHCl3)=−7.7; lit. [α]25 (c 1.04, CHCl3)=−6.5.

Provenance & Evidence