Oxidation of 1,4‐dihydro‐1,4‐diphenyl‐2,3‐benzodithiin

Abstract

Abstract1,4‐Dihydro‐1,4‐diphenyl‐2,3‐benzodithiin (3), synthesized from 1,2‐bis(phenylmethyl)benzene (1), was subjected to oxidation to give 1,4‐dihydro‐1,4‐diphenyl‐2,3‐benzodithiin 2‐oxide (4) as a mixture of diastereomers separable by column chromatography. (1R*,2R*,4S*)‐1,4‐Dihydro‐1,4‐diphenyl‐2,3‐benzodithiin 2‐oxide (4‐meso‐1) was obtained preferentially from (1R*,4S*)‐1,4‐dihydro‐1,4‐diphenyl‐2,3‐benzodithiin (3‐meso) with m‐chloroperbenzoic acid (m‐CPBA). The 4‐meso‐1 stereoisomer afforded an unexpected product 1,3‐diphenylbenzo[c]thiophene (5) upon further oxidation with mCPBA. On the other hand, oxidation of 1,4‐dihydro‐1,4‐diphenyl‐2,3‐benzodithiin 2‐oxides (4‐dl and 4‐meso), with Oxone gave 1,4‐dihydro‐1,4‐diphenyl‐2,3‐benzodithiin 2,2‐dioxide (7). © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:209–216, 2001

cis-2,2-Dimethyl-1,3-diphenyl-2,3-dihydro-1H-benzo[c]silole

“…The first step prepares the carbon diacid, (1), by Friedel-Crafts alkylation of benzene with α,α′-dichloro-o-xylene (Mataka et al,1981). The carbon acid is bislithiated using two equivalents of n-butyl lithium and tetramethylethylenediamine (TMEDA) to give the deep-red dicarbanion, (2) (Sato et al, 2001), which, upon reaction with diphenyldichlorosilane, gives the title compound, (3). The major isomer is the crystalline cis-isomer.…”

Sulfur and Phosphorus Peroxides

“…166 . When compound 38 was treated with m-CPBA in CH 2 Cl 2 , ring contraction to 1,3-diphenylbenzo[c]thiophene 39 was observed.…”