Synthesis of porphobilinogen via a novel ozonide cleavage reaction.
نویسندگان
چکیده
Porphobilinogen lactam methyl ester (3a) has been prepared in seven steps, and approximately 20-30% overall yield, beginning with furfurylamine (4a).(24) Hydrolysis of 3a following the literature procedure then gave porphobilinogen (1). A key intermediate in our synthesis of 3a is the 7-oxonorbornene derivative 7a, which was derived from 4a utilizing a tandem Johnson ortho ester Claisen rearrangement followed by intramolecular Diels-Alder cyclization (five steps, 55-65%).(24) Interesting steric accelerating effects were observed in this sequence. Conversion of 7a to 3a was then accomplished employing a novel ozonide cleavage/oxidation reaction, which generated tetrahydrofurans 16a, 32, and 33 in the proper oxidation state for direct aminolysis to pyrrole 3a. A mechanism is proposed for the ozonide cleavage/oxidation that accounts for the observed stereoselectivity of this step.
منابع مشابه
Microwave-Assisted Synthesis of Novel Functionalized Ketenimines and Azadienes via a Solvent-Free Reaction of Isatoic Anhydride, Alkyl-Isocyanides and Dialkyl Acetylenedicarboxylates
Ketenimines and azadienes are transient intermediates in organic chemistry especially in elimination-addition processes and in the formation of heterocyclic systems. These compounds play a considerable role as intermediates in the synthesis of heterocyclic ring systems. In this present research synthesis of novel ketenimines and azadienes via multicomponent reactions (MCRs...
متن کاملMCM-BP as a Novel Nanomagnetic Reusable Basic Catalyst for the one Pot Solvent-Free Synthesis of Dihydropyridine, Polyhydroquinoline and Polyhydroacridine Derivatives via Hantzsch Multicomponent Condensation Reaction
By the immobilization of bipyridinium chloride onto mesoporous MCM-41encapsulated Fe3O4 nanoparticles via a simple post-synthesis method, a totally new organic-inorganic hybrid nanocomposite was formulated. The heterogeneous hybrid nanomagnetic composite was characterized by <spa...
متن کاملSynthesis of Novel Fluorene Bisamide Derivatives via Ugi Reaction and Evaluation their Biological Activity against Mycobacterium species
A series of new fluorene bisamide derivatives were synthesized through multi-component Ugi reaction and tested for their in vitro anti-mycobacterial activity. The structures of the products 5a-w were deduced from their IR, 1H NMR, and 13C NMR spectra. Elemental analyses (CHN) for novel compounds (5a, 5d, 5f, 5h, 5k, 5l, 5p, 5s, 5t, 5v, 5w) was done to. These compounds were evaluated as anti-bac...
متن کاملSynthesis of Novel Fluorene Bisamide Derivatives via Ugi Reaction and Evaluation their Biological Activity against Mycobacterium species
A series of new fluorene bisamide derivatives were synthesized through multi-component Ugi reaction and tested for their in vitro anti-mycobacterial activity. The structures of the products 5a-w were deduced from their IR, 1H NMR, and 13C NMR spectra. Elemental analyses (CHN) for novel compounds (5a, 5d, 5f, 5h, 5k, 5l, 5p, 5s, 5t, 5v, 5w) was done to. These compounds were evaluated as anti-bac...
متن کاملA Novel protocol for synthesis of Hantzsch 1, 4- dihydropyridines using PEG-400 as a reaction medium and under catalyst-free condition
An efficient and expeditious catalyst-free procedure was developed for the one- pot synthesis of 1, 4-dihydropyridine derivatives via the three-component reaction of various aldehydes, ethyl acetoacetate, and ammonium acetate in PEG-400. The reaction was carried out at 110°С and the products were obtained in good to high yields.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of the American Chemical Society
دوره 123 38 شماره
صفحات -
تاریخ انتشار 2001