Benz pyran

Benz Derivatives of Pyrans, Pyrones, and Their Sulfur Analogues. 298... 

Several synthetic compounds containing the naphthoquinone skeleton, such as 2-(4-cyclohexylcyclohexyl)-3-hydroxy- 1,4-naphthoquinone [169], are effective in the treatment of coccidial infection. Two structurally related antibiotics WS-5995A (36) and WS-5995B (37a), isolated from S. auranticolor sp. nov. near Tokyo, efficiently protect Eimeria tenella (a species of coccidia) infection. An inactive component WS-5995C (37b) can be readily converted to the active (36) by simple dehydration [ 170-172]. Compound (36), the structure of which resembles the aforementioned benz[a]anthraquinone antibiotics, is the first example of a 5//-benzo[d ]naphtho[ 2,3-6 ]pyran ring system found in nature. 

Benz> loxy)-2,2-bis(triflooroinethyl)-2,3,5,6-tctrahvdro-4A/-pyran-4-oiie (11) Typical Procedure ... 

A highly efficient and operationally simple domino reaction was developed in the laboratory of S. Ruchiwarat for the synthesis of benz[h]indeno[2,1-e]pyran-10,11-diones. The initial aroyl-transfer was achieved by the Baker-Venkataraman rearrangement by subjecting the starting material to KOH in pyridine under reflux for 30 minutes. 

Thasana, N., Ruchirawat, S. The application of the Baker-Venkataraman rearrangement to the synthesis of benz[b]indeno[2,1-e]pyran-10,11-dione. Tetrahedron Lett. 2002, 43, 4515-4517. 

The interaction between benz aldehyde and acetic anhydride in the presence of sodium acetate results into the formation of the heterocyclic pyran ring to give coumanin in addition to a mole each of acetic acid and water as products of reaction. 

Pyran ring enlargement in a dihydrospectinomycin derivative gave modified antibiotics, homo-spectinomycins are derivatives of perhydrooxepino[2,3-Z>]benz-l,4-dioxane, which exhibited bactericidal activity <88JAN1445>. 

Benzimidazolyl) thiazol. See Thiabendazole Benzin. See Gasoline VM P naphtha Naphtha 2,3-Benzindene. See Fluorene Benz (b) indeno (1,2-d) pyran-3,4,6a,9,10(6H)-pentol, 7,1 Ib-dihydro-, (6as-cis)-. See Hematoxylin Benzine. See Naphtha 1-Benzine. See Quinoline Benzine (light petroleum distillate). See VM P naphtha... 

Other Names Benz[b]indeno[l,2-d]pyran-3,4,6a,9,10(6H)-pentol, 7,llb-dihydro Benz[b]indeno [l,2-d]pyran-3,4,6a,9,10(6H)-pentol, 7,llb-dihydro, (6aS-cis)- (+)-Hematoxylin Haematoxylin Hematoxylin Hematoxyline Hydroxybrasilin Hydroxybrazilin NSC 270085 CA Index Name Benz[b]indeno[l,2-d]pyran-3,4,6a,9,10(6H)-pentol, 7,llb-dihydro, (6aS,llbR)-CAS Registry Number 517-28-2 Merck Index Number 4637 Chemical Structure... 

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