The photobiology of the gilvocarcins. Total synthesis of defucogilvocarcin V and a related photoactive vinyl phenol

Synthetic approaches toward mitomycins: construction of p-quinone moiety on 1-benzazocine derivative

“…6,9-Dimethyl-5,5-(ethylenedioxy)-7-hydroxy-8-methoxyl-(p-tolylsulfonyl)-l,2,3,4,5,6-hexahydro-l-benzazocine (12). To a suspension of lithium aluminum hydride (1.25 g, 33.0 mmol) in 20 mL of dry THF was added dropwise a solution of 10A (3.97 g, 10.0 mmol) in 50 mL of THF at 0 °C.…”

“…(11) Chan, T. H.; Brook, M. A.; Chaly, T. Synthesis 1983, 203. (12) Oda, K.; Ohnuma, T.; Ban, Y.; Aoe, K. J. Am.…”

An Inverse Electron Demand Diels–Alder-Based Total Synthesis of Defucogilvocarcin V and Some C-8 Analogues

“…The solids were vacuum-dried for 2 h and then dried under air in an oven at 90−100 °C for 12 h to afford 26 (91 mg, 86%) as a pale yellow solid. R f = 0.20 (ethyl acetate); mp 197−200 °C; IR (neat) ν = 3300−2400 (br, w), 1733 (m), 1689 (s) cm −1 ; 1 H NMR (DMSO-d 6 , 500 MHz) δ 8.41 (d, J = 1.6 Hz, 1H), 8.34 (s, 1H), 8.01 (d, J = 8.4 Hz, 1H), 7.90 (d, J = 1.7 Hz, 1H), 7.57 (t, J = 8.1 Hz, 1H), 7.24 (d, J = 7.7 Hz, 1H), 5.29 (s, 2H), 4.14 (s, 3H), 3.95 (s, 3H), 3.52 (s, 3H); 13 8-(Hydroxymethyl)-10,12-dimethoxy-1-(methoxymethoxy)-6H-benzo[d]naphtho [1,2-b]pyran-6-one-8-carboxylic Acid (27). To a 0 °C suspension of 26 (80 mg, 0.20 mmol) in THF (8.0 mL) was added H 3 B•SMe 2 (0.60 mL, 1.2 mmol) dropwise over a period of 5 min, and the resulting mixture was stirred at room temperature for 5 h. The reaction mixture was cooled to 0 °C, methanol (1 mL) was added dropwise, and the solvent was removed under reduced pressure.…”

“…Whereas only a handful of total syntheses of gilvocarcins have been accomplished, − a relatively large number of defucogilvocarcin syntheses has been reported. The strategies used to approach the defucogilvocarcins can be sorted into three categories according to the ring(s) generated during the key step(s): (1) formation of the C ring using (a) Suzuki coupling followed by lactonization, − (b) esterification/intramolecular biaryl bond formation, (c) nucleophilic aromatic substitution/lactonization, , (d) Pechmann condensation, and (e) conjugate addition/lactonization; (2) formation of the A and C rings using (f) Diels–Alder reaction (A ring)/Meerwein coupling/lactonization (C ring); − and (3) formation of the B and C rings using (g) a Dötz chromium carbene benzannulation/lactonization, (h) a [2 + 2] cycloaddition/pericyclic ring-opening–ring closing/lactonization, and (i) a condensation reaction between a styryl sulfone and a phthalide . More recently, a one-pot enzymatic synthesis of defucogilvacarcin M starting from acetyl-CoA and malonyl-CoA using 15 enzymes has been reported .…”

Synthesis and Evaluation of a Novel Nonsteroidal-Specific Endothelial Cell Proliferation Inhibitor

“…Although the dibenzo[ b , d ]pyran-6-one scaffold has not been used frequently in pharmaceuticals, it is found in naturally occurring compounds exemplified by alternariol, ellagic acid, and the benzo[ d ]naphthopyran-6-one gilvocarcin V as shown in Scheme . Ellagic acid inhibits the mutagenicity of polycyclic aromatic hydrocarbons in vivo, and gilvocarcin V has significant in vitro antitumor activity when activated by low-energy light.…”