Untitled

Highly Diastereoselective Allylic Azide Formation and Isomerization. Synthesis of 3(2‘-Amino)-β-lactams

“…The complete selectivity of the rearrangement was rationalized by the mechanism proposed in Figure , where a concerted [3,3]-sigmatropic rearrangement occurs via a cyclic transition state with complete stereocontrol, in accordance with the mechanisms suggested for the interconversion of allylic azides 4 Mechanism proposed for the [3,3]-sigmatropic rearrangement. …”

(Z)-Selective Enol Triflation of α-Alkoxyacetoaldehydes: Application to Synthesis of (Z)-Allylic Alcohols via Cross-Coupling Reaction and [1,2]-Wittig Rearrangement

“…IR (neat): 3035, , 1092 (Z)-1,3-Diphenylprop-2-en-1-ol (4Aa). 31 To a solution of 3Aa (63 mg, 0.3 mmol, Z/E = 95/5) in THF (3 mL) was added n-BuLi (0.56 mL of 1.62 M solution in hexane, 0.9 mmol) at 0 °C under Ar atmosphere and the reaction mixture was stirred at 0 °C for 10 min. The reaction was quenched with water.…”

A Novel Approach to Substituted 2H-Azirines

“…2-Benzyl-3-phenyl-2 H -azirine (5a). Oil (70%); 1 H NMR δ 7.77−7.75 (m, 2H), 7.55−7.47 (m, 3H), 7.31−7.21 (m, 5H), 3.06 (dd, J = 14.6, 5.1, 1H), 2.76 (dd, J = 14.6, 5.1 Hz, 1H), 2.51 (t, J = 5.1 Hz, 1H); 13 C NMR δ 171.6, 139.3, 132.8, 129.3, 129.0, 128.9, 128.5, 126.3, 125.5, 40.1, 33.2.…”

“…White prisms (93%), mp 234-236 °C (lit. 14 2, 145.3, 134.4, 133.3, 129.6, 128.8, 127.9, 126.7, 124.5, 119.6, 110.9, 41. .53 (m, 3H), 7.37 (dd, J ) 8.0, 7.3 Hz, 1H), 7.12 (d, J ) 8.0 Hz, 2H), 6.07 (s, 2H), 2.24 (s, 3H); 13 C NMR (DMSO-d6) 150.6, 144. 9, 138.8, 132.8, 131.1, 128.9, 127.4, 126.2, 124.0, 119.1, 110.4, 41.0, 20.7 General Procedure for 2-(Benzotriazol-1-yl)-2H-azirines 4a-c. To a solution of oxime 2 (20 mmol) in a mixture of ethyl ether (150 mL) and chloroform (50 mL) was added dropwise aqueous KOH (11.2 g of KOH dissolved in 50 mL of water) at 0 °C.…”