Abstract
1,5-C ,C -Cycloalkylation of tert -butyl acetoacetate (1 ) with cis -1,4-dichloro-2-butene (2 ) followed by the haloform reaction of the product in NaOH solution and subsequent Curtius degradation in tert -butyl alcohol furnished tert -butyl 1-tert -butoxycarbonylaminocyclopent-3-enecarboxylate (5 ) in 32% overall yield.
Key words
alkenes - cyclizations - excitatory amino acids - haloform reaction - Curtius rearrangement
References
1 Moloney MG.
Nat. Prod. Rep.
2002,
19:
597 ; and references cited therein
2 Moher ED, Monn JA, and Pedregal-Tercero C. inventors; (Eli Lilly and Company); US Pat. WO 2003104217.
; Chem. Abstr . 2004 , 140 , 42463. A financial reward was also offered by InnoCentive for an efficient synthetic route to this compound (challenge 3100). No solution has ever been accepted; however, the collected ideas obviously were used in the patent application cited above
3a Dias EL.
Nguyen ST.
Grubbs RH.
J. Am. Chem. Soc.
1997,
119:
3887
3b Cetinkaya B.
Demir S.
Oezdemir I.
Toupet L.
Semeril D.
Bruneau C.
Dixneuf PH.
Chem.-Eur. J.
2003,
9:
2323
3c Wybrow RAJ.
Johnson LA.
Auffray B.
Moran WJ.
Adams H.
Harrity JPA.
Tetrahedron Lett.
2002,
43:
7851
3d Connon SJ.
Blechert S.
Bioorg. Med. Chem. Lett.
2002,
12:
1873
3e Gibson SE.
Swamy VM.
Adv. Synth. Catal.
2002,
344:
619
3f Kotha S.
Sreenivasachary N.
Bioorg. Med. Chem. Lett.
1998,
8:
257
3g Kotha S.
Sreenivasachary N.
Mohanraja K.
Durani S.
Bioorg. Med. Chem. Lett.
2001,
11:
1421
3h Hammer K.
Undheim K.
Tetrahedron
1997,
53:
2309
3i Cockbain J, Undheim K, and Hammer K. inventors; Int. Pat. WO 9830535 A1.
; Chem. Abstr . 1998 , 129 , 136491
4 Depres J.-P.
Greene AE.
J. Org. Chem.
1984,
49:
928
5a Park K.-H.
Olmstead MM.
Kurth MJ.
J. Org. Chem.
1998,
63:
6579
5b Park K.-H.
Kurth TH.
Olmstead MM.
Kurth MJ.
Tetrahedron Lett.
2001,
42:
991
6 O’Donnell MJ.
Aldrichimica Acta
2001,
34:
3
7
tert -Butyl N -(diphenylmethylene)glycinate is commercially available at a price of 46.60 EUR per 1 g (Aldrich).
8a Doller D.
Chackalamannil S.
Stamford A.
McKittrick B.
Czarniecki M.
Bioorg. Med. Chem. Lett.
1997,
7:
1381
8b Amori L.
Costantino G.
Marinozzi M.
Pellicciari R.
Gasparini F.
Flor PJ.
Kuhn R.
Vranesic I.
Bioorg. Med. Chem. Lett.
2000,
10:
1447
8c Hodgson DM.
Thompson AJ.
Wadman S.
Keats CJ.
Tetrahedron
1999,
55:
10815
8d Hodgson DM.
Thompson AJ.
Wadman S.
Tetrahedron Lett.
1998,
39:
3357
9 The price of methyl tert -butyl malonate is 45.00 EUR for 10 mL (Aldrich).
10 The price of tert -butyl acetoacetate(1 ) is 43.20 EUR for 500 mL (Aldrich).
11
cis -1,4-Dichloro-2-butene(2 ) is commercially available at a price of 133.00 EUR for 100 g (Aldrich).
12a Weinstock J.
J. Org. Chem.
1961,
26:
3511
12b Jendralla H.
Chem. Ber.
1980,
113:
3585
13 Without tin tetrachloride, the yield was only 17%.
14 Diphenylphosphoryl azide (DPPA) is commercially available at a price of 136.35 EUR for 100 g (Aldrich) or else can easily be prepared.15
15 Shioiri T.
Ninomiya K.
Yamada S.-I.
J. Am. Chem. Soc.
1972,
94:
6203
