Intramolecular [2+2] Cycloaddition of Homoallylketenes to Bicyclo[2.1.1]hexan-5-ones

Dual Activity of Grubbs-Type Catalyst in the Transvinylation of Carboxylic Acids and Ring-Closing Metathesis Reactions

“…Carboxylic acids 1f , , 1g , 1h , 1i , , 1k , , 1m , and 1n were synthesized and purified according to the literature procedure. The 1 H and 13 C NMR data were in accordance with those reported in the literature.…”

Saturated Bioisosteres of ortho‐Substituted Benzenes

“…Moreover, at least one substituent must be a functional group that can be further modified during incorporation into bioactive compounds. In this context, it is worth mentioning a recent work of Matsuo and co‐workers, who developed an approach to substituted ketones B [16] . However, further modification of the ketone group was not elaborated.…”

“…[15] However,w en eeded as ynthetic approach that would give core B with only two substituents at the specific bridgehead and side-chain positions.M oreover,a tl east one substituent must be af unctional group that can be further modified during incorporation into bioactive compounds.I n this context, it is worth mentioning ar ecent work of Matsuo and co-workers,w ho developed an approach to substituted ketones B. [16] However, further modification of the ketone group was not elaborated.…”

Saturated Bioisosteres of ortho‐Substituted Benzenes

“…[15] However,w en eeded as ynthetic approach that would give core B with only two substituents at the specific bridgehead and side-chain positions.M oreover,a tl east one substituent must be af unctional group that can be further modified during incorporation into bioactive compounds.I n this context, it is worth mentioning ar ecent work of Matsuo and co-workers,w ho developed an approach to substituted ketones B. [16] However, further modification of the ketone group was not elaborated.…”

“…[19] All syntheses were started from the corresponding (hetero)aromatic acids that are commercially available.T he photochemical step was tolerated by the presence of methoxy (2a), fluorine (3a), trifluoromethyl (4a), chlorine (5a)a nd bromine substituents (6a, 7a)( Scheme 3). More importantly,t he photochemical step worked also with diverse heterocycles:t hree isomeric pyridines (8-10), oxazole (11), thiophene (12), pyrazoles (13,15), thiazoles (14,16), and furan (17)g ave the desired products 2a-17 a in good yields.Amixture of isomers was obtained in each case.A fter none-selective alkali hydrolysis, diastereomeric ratio of the obtained acids remained the same. As ingle crystallization from hexane allowed isolating the major components 1b-17 b as single stereoisomers.A ll products were synthesized on ag ram scale.S tructures of acids 13 b, 15 b and 16 b were confirmed by X-Ray analysis (Scheme 3).…”