21464-41-5Relevant academic research and scientific papers
Electron-transfer-induced reductive cleavage of phthalans: Reactivity and synthetic applications
Azzena, Ugo,Demartis, Salvatore,Melloni, Giovanni
, p. 4913 - 4919 (2007/10/03)
The behavior of phthalan (1a) was investigated under conditions of electron transfer from alkali metals in aprotic solvents. Reaction with lithium in the presence of a catalytic amount of naphthalene in THF led to the reductive cleavage of an arylmethyl carbon-oxygen bond, with formation of a stable dilithium compound. Trapping of this intermediate with several electrophiles (alkyl halides, carbonyl derivatives, CO2) was successful. The extension of this procedure to several substituted phthalans (1b-i) was investigated, and the regiochemistry as well as the synthetic usefulness of these reactions are discussed.
A Novel Synthesis of Naphthalenic Lignan Lactones
Patil, P. A.,Joshi, R. R.,Narasimhan, N. S.
, p. 1025 - 1029 (2007/10/02)
Hydroxyphthalans (2) are obtained either through selective reaction of aryllithiums with phthalides (3a,b) or selective reduction of the formyl group in o-formylbenzophenones (7).They are then converted into naphthalenic diesters (5), through isobenzofura
Direct ortho-Metalation of Benzyl Alcohols. A Novel Method of Preparing ortho-Substituted Benzyl Alcohols
Meyer, Norbert,Seebach, Dieter
, p. 1304 - 1319 (2007/10/02)
Benzyl alcohol and other phenylcarbinols (8a - 11a), including α-tetralol (12a), are doubly deprotonated by excess n-butyllithium/TMEDA in pentane to give lithium ortho-lithioalkoxides (2, 8b - 12b).Alkylations (-> 3a - d, table 1), reactions with heteroelectrophiles (-> 3e - k, table 2) and with carbonyl compounds (-> 6, 13 - 17, tables 3 and 4), as well as subsequent reactions of the primary adducts (-> phthalanes 7, table 3) furnish a large variety of ortho-substituted benzyl alcohol derivatives.The scope and limitations of the dilithioorganyls (sections B and C), their mode of formation (section A), and attempts to doubly metalate 2-phenylethanol are discussed.
Ring-chain tautomerism as a factor in the reaction between Grignard reagents and substituted phthalides
Smith,Wikman
, p. 2603 - 2611 (2007/10/04)
With phthalide two equivalents of Grignard reagent react rapidly in a reaction which could not be controlled to give stepwise addition. In contrast, 3,3- and 4,7-disubstituted phthalides react with only one equivalent of organometallic reagent. The primary addition product formed from one equivalent each of phthalide and Grignard reagent exists in a ring-chain tautomerism whose position is controlled by the interaction between the substituents present in the phthalide and the alkyl group introduced by the Grignard reagent. With substituted phthalides, ring opening of the primary addition product is prevented by these interactions and thus a second equivalent of Grignard reagent does not react. In the absence of substituents, ring opening and the reaction of a second equivalent occurs. Somewhat related effects appear to exist in the reaction between Grignard reagents and phthalic anhydride and in the dehydration of substituted phthalyl alcohols to their corresponding phthalans.
