An extremely short synthesis of the prostaglandin key intermediate through a novel vinyl anion equivalent

New type of cyclization of .alpha.,.beta.,.chi.,.psi.-unsaturated dioic acid esters through tandem conjugate additions by using lithium N-benzyl-N-(trimethylsilyl)amide as a nitrogen nucleophile

“…d, J = 6.1 Hz, H-2), 1.58-1.20 (13 H, m), and 0.89 (3 H, t, J = 6. 5 Hz, H-10); exact mass found m/z 291.2197, caled for C18H2sN02 M, 291.2198. Anal.…”

“…12 (c-3-(JV-benzylamino)-t-2-(methoxycarbonyl)cyclopentane-l-acetate, the major isomer): NMR (600, CDCI3) 7.36-7.17 (5 H, m, -Ph), 3.77 (1 H, d, J = 13. 5 Hz,-CHHPh), 3.72 (1 H, d,J= 13.5Hz,-CHHPh), 3.69 (3 H, s, -COjMe), 3.65 (3 H, s, -C02Me), 3.38 (1H, ddd, «f3i2 = Jmdt) = J34(tnm) = 7.9 Hz, H-3), 2.59 (1 H, m, H-l), 2.56 (1 H, dd, J = 15Í6 and 5.8 Hz, -CHHC02Me), 2.37 (1 H, J = 15.6 and 8.0 Hz, -CHHCOgMe), 2.34 (1 H, dd, J2utm») = 9-2 and J23 = 7.9 Hz, H-2), 2.00-1.90 (2 H, m, H-4 and NH), and 1.62-1.44 (3 H, m).…”

“…= Jsm<*) = 4. 5 Hz, H-5), and 1.15 (3 H, t, J = 7.1 Hz); exact mass found m/z 212.1027, caled for CuH1604 M, 212.1049.…”

“…6 Hz, H-3), 3.74 (3 H, s, -C02CH3), 3.61 (3 H, s, -C02CH3), 3.22 (1 H, dddd, JiMtim) = 8.0, J1,6(0,) = = 4.5, = 1.6 Hz, H-l), 3.09 (1 H, qd, Ji',m« = 7.1 and JVA = 4. 5 Hz, -CH(CH3)C02CH3), 2.40 (2 H, m, H-4),…”

“…6 Hz, H-3endo), 4.03 (1 H, ddd, J3g(mm) * 10j6, J34(trua) = 3.8, and «/34a = 1. 5 Hz, H-3exo), 2.52 (1 H, m, H-4a), 2.43 (1 H, dd, «/7a,7(tnuul) = 10.6 and «/7Ma = 9.4 Hz, H-7a), 2.24 (1 H, dqd, «/4rg(cja) = 10.6, J4im, * 6.4, «/4l3(d») = 3.8 Hz, H-4), 2.0Q ( 1H, m, H-7), 1.92 (1H, broad ddd, J = 12.0,6.2, and 6.2 Hz, W1/2 = 3 Hz, H-6), 1.75 (1H, dddd, J = 13.2,12.6,7.2, and 2. 6 Hz, H-5), 1.44 (1 H, dddd, J -12.…”