反应详情

Reaction of the auxiliary (5) (0.577 g, 4.47 mmol) in solution in tetrahydrofuran (20 ml) at -78° C. with butyllithium (1.6M, 2.82 ml, 4.52 mmol) and propionyl chloride (0.427 ml, 4.92 mmol) for 30 minutes and then at room temperature for 1 hour, with work-up and recrystallisation from 40-60 petroleum ether furnished the title compound (17) as a solid (0.780 g, 94%); mp 86° C.; v. (CHCl3) 1703 and 1781 cm-1 ; [α]D 25 (c 0.9 in CHCl3)=+58.1; (Found: C, 58.08; H, 7.85; N, 7.53. C9H15NO3 requires C, 58.36; H, 8.16; N, 7.56%); δH (CDCl3 ; 300 MHz) 1.05 (3H, t, J=7.4, CH3CH2), 1.18 (3H, d, J=6.5, CHCH3), 1.31 (3H, s, C(CH3)2), 1.34 (3H, s, C(CH3)2), 2.82 (2H, q, J=7.3, CH2CH3), 4.09 (1H, q, J=6.5, CHCH3); δC (125 MHz; CDCl3) 8.08 (CH3), 14.41 (CH3), 21.30 (CH3), 27.58 (CH3), 29.09 (CH2), 58.72 (CH), 81.36 (C), 152.91 (CO), 174.49 (CO) ; m/z (CI+, NH3) 186 (M+ +1).

1. customwith work-up and recrystallisation from 40-60 petroleum ether