Oxidation of several thiol derivatives by a combination of N-chlorosuccinimide and dilute hydrochloric acid proceeded smoothly, affording the corresponding sulfonyl chlorides in good yield.

A combination of sulfanyl radical addition-cyclization of dienes connected with hydroximates and subsequent conversion of the resulting cyclic hydroximate to the lactones provides a novel method for the construction of alpha,beta-disubstituted gamma-lactones. Upon treatment with thiophenol in the presence of AIBN, dienes connected with hydroximates smoothly underwent sulfanyl radical addition-cyclization to give cyclic cis- and trans-hydroximates. Hydrolysis of cyclic hydroximates gave the desired cis- and trans-lactones in high yield. This method was successfully applied to the practical synthesis of (+/-)-oxo-parabenzlactone.

Substantial progress has been described in the development of asymmetric variants of the phosphine-catalyzed intermolecular [3+2] annulation of allenes with alkenes; however, there have not been corresponding advances for the intramolecular process, which can generate a higher level of complexity (an additional ring and stereocenter(s)). In this study, we describe the application of chiral phosphepine catalysts to address this challenge, thereby providing access to useful scaffolds that are found in bioactive compounds, including diquinane and quinolin-2-one derivatives, with very good stereoselectivity. The products of the [3+2] annulation can be readily transformed into structures that are even more stereochemically rich. Mechanistic studies are consistent with β addition of the phosphepine to the allene being the turnover-limiting step of the catalytic cycle, followed by a concerted [3+2] cycloaddition to the pendant olefin.

A practical method of synthesizing 7-{4-[2-(butoxy)ethoxy]phenyl}-N-(4-{[methyl(tetrahydro-2H-pyran-4-yl)amino]methyl}phenyl)-1-propyl-2,3-dihydro-1H-1-benzazepine-4-carboxamide (8), an orally active CCR5 antagonist, has been developed. Methyl 7-bromo-1-propyl-2,3-dihydro-1H-1-benzazepine-4-caboxylate (14a) was synthesized in good yield by the esterification of 4-[(4-bromo-2-formylphenyl)(propyl)amino]butanoic acid (13) followed by an intramolecular Claisen type reaction with 28% sodium methoxide in dimethyl carbonate as a solvent in one pot. The Suzuki−Miyaura reaction of 14a and 1-bromo-4-(2-butoxyethoxy)benzene (10) followed by hydrolysis and amidation gave 8. A new inexpensive method without chromatographic purification was established.