close

Вход

Забыли?

вход по аккаунту

?

Carbonyliron-Assisted Cycloaddition of a 1 3-Diene to a CC Double Bond Synthesis of an Anthracyclinone Precursor.

код для вставкиСкачать
COMMUNICATIONS
( OC I4Fe-
1
2
3, exo - F e ( C O ) 3
3'. endo -Fe(CO),
H
a
4, e ~ o - F e ( C 0 ) ~
5
4', endo -Fe(CO),
I
Carbonyliron-Assisted Cycloaddition of a
1,3-Diene to a CC Double Bond:
Synthesis of an Anthracyclinone Precursor**
By Philippe Vioget, Pierre Vogel, and Raymond Roulet*
The cycloaddition of a 1,3-diene to a monoolefin coordinated to a transition metal has not been reported so far.
The reaction is unfavored as the final cyclohexene complex would be coordinatively unsaturated[']. It can occur,
however, if the required extra ligand is incorporated into
the dienophile'21or if the dienophile is a C C triple bondf3].
We report the first case of a formal [4+2] cycloaddition
in which the dienophile is complexed by carbonyliron,
namely the cyclodimerization of 5,6-bismethylene-7-oxabicyclo[2.2.l]hept-2-ene 1 in presence of Fe2(CO),, the extra
ligand being probably the oxygen bridge of the oxanorbornene system.
The reaction between 1 and Fe2(CO), in pentane yields
the mono- and dimetallic complexes 2, 3 and 3'14].In methanol at 50°C, the complexes 4 and 4 (30%, yellow crystals, m.p.= 128-129 and 175--177"C, respectively), the
diene 5 (9.3%; colorless crystals; m.p.= 130-131 " C ; 'HNMR (360 MHz, CDC13, TMS): 6=7.13 (m, 4H), 5.22/
4.98 ( 2 ~ 2, ~ 2 H =CH2),
,
4.61 (s, 2 H , H-1,8), 2.90/2.57/
2.16 (3 m, 3 x 2 H, ' J = 13.5 Hz, 3 J = 5.0 and 9.0 Hz); I3CNMR (90.55 MHz, CDC13, TMS): 6 = 148.0/138.4 ( 2 ~ ) ,
126.9 (dd, 'J(CH)= 154 Hz, ' J = 5 Hz); 126.3 (dd, ' J = 159
Hz, 3 J = 9 Hz), 101.0 (t, 160 Hz), 86.7 (d, 154 Hz), 44.8 (d,
137 Hz), 32.3 (t, 128 Hz)), and the ortho-quinodimethane
complexes 6 (6.5%) and 7 (3%) were formed. Heating 2 in
methanol (50°C) gave 4 (330/0), 5 (119/0), and 6 (14%).
Heating 3 in
Thermolysis of 3 in toluene gave 6 (60Y0)~~'.
methanol, ethanol, and 2-propanol gave the esters 7-9.
Control experiments confirmed that the cyclodimerization
[*] Prof. Dr. R. Roulet, P. Vioget
lnstitut d e chimie minerale et analytique de I'Universite
Place du ChHteau 3, CH-1005 Lausanne (Switzerland)
Prof. Dr. P. Vogel
lnstitut d e Chimie organique d e I'Universitk
Rue d e la Barre 2, CH-1005 Lausanne (Switzerland)
[**I We thank the Schweizerische Nationalfonds zur Forderung der wissenschaftlichen Forschung ( F N 2.882-0.80, 2.456-0.79) for financial support.
430
0 Verlag Chemie GmbH. 6940 Weinheim. 1982
4O0C
RoH
R
, *J-fJ
\6
4 Fe(CO),
7, R
8, R
9, R
= CH,(81%)
CH,CH2(55%)
= (CH,),CH(38%)
occurred only with the monometallic complex 2. Oxidation
of 4 and 4 by (CH3)3N0 in acetone furnished 5 (98%, relative to 2 : 41%). The coupling constant JI.H.2.H':0 Hz in
4 , 4', and 5 confirmed the exo-annelation.
10
11
Irradiation of 1 in C H 3 0 H in presence of Fe2(C0), at
- 20°C results in formation of the cyclopentanone derivative 10: reaction of 1 and R U ~ ( C Oin) ~toluene
~
(65"C, 7
d) results in isolation of the furan 11 in 10% yield, in addition to 10% of 5 .
The reaction sequence 2-4-5
gives a simple route to
the synthesis of bismethylene compounds 5 , a potential
precursor for the preparation of antitumor agent 4-demethoxydaunomycinone[81.
Received: April 16, 1981 [Z 97 IE]
revised: April I , 1982
German version: Angew. Chem. 94 (1982) 454
The complete manuscript of this communication appears in:
Angew. Chem. Suppl. 1982, 1128-1 137
[I] F:W. Grevels, U. Feldhoff, J. Leitich, C. Kriiger, J. Organomef. Chem.
118 (1976) 79; F.-W. Grevels, K. Schneider, Angew. Chem. 93 (1981) 417;
.4ngew. Chem. I n f . Ed. Engl. 20 (1981) 410.
[2] A. Mortreux, J. C. Bavay, F. Petit, Nouu. J. Chimie 4 (1980) 671 and references cited therein; G. N. Schrauzer, P. Glockner, Chem. Ber. 97 (1964)
2451; W. Brenner, P. Heimbach, H. Hey, E. W. Miiller, G. Wilke, Jusfus
Liebigs Ann. Chem. 727 (1969) 161: P. Heimbach, G. Wilke, ibid. 727
(1969) 183: P. J. Garratt, M. Wyatt, J. Chem. SOC.Chem. Commun. 1974,
251.
[3] W. Brenner, P. Heimbach, G. Wilke, Justus Liebigs Ann. Chem. 727(1969)
194: J. P. Genet, J. Ficini, Tefrahedron L e f f .1979. 1499: P. Heimbach, Angew. Chem. 85 (1973) 1035; Angew. Chem. Inr. Ed. Engl. I2 (1973) 975.
[4] A. A. Pinkerton, P. A. Carrupt, P. Vogel. T. Boschi, N. H. Thuy, R. Roulet, Inorg. Chim. Acta 28 (1978) 123.
[S] Y. Bessiere, P. Vogel, Helu. Chim. Acta 63 (1980) 232 and references cited
therein.
05/0-08.13/82/0606-043f~ $ 02.50/0
Angew. Chem. Inf. Ed. Engl. 21 (1982)
No. 6
Документ
Категория
Без категории
Просмотров
0
Размер файла
240 Кб
Теги
bond, assisted, synthesis, cycloadditions, diener, anthracycline, double, precursors, carbonyliron
1/--страниц
Пожаловаться на содержимое документа