<span style="font-size:12.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-ansi-language: EN-IN;mso-fareast-language:EN-IN;mso-bidi-language:AR-SA" lang="EN-IN">Synthesis of <i style="mso-bidi-font-style:normal">anti</i>-[2.2](2.6)benzothiazolophane via 10π-10π: coupling protocol</span>

Abstract

<span style="font-size:12.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">The known 6-methoxymethyl-2-methylbenzothiazole <b style="mso-bidi-font-weight:normal">6</b> has been converted into quaternary ammonium hydroxide <b style="mso-bidi-font-weight: normal">4</b> via demethoxy-bromination followed by quaternization with (CH₃)₃N and treatment with silver oxide. Pyrrolysis of <b style="mso-bidi-font-weight: normal">4</b>, expected to generate both <i style="mso-bidi-font-style:normal">anti</i>-<b style="mso-bidi-font-weight:normal">1</b> and <i style="mso-bidi-font-style: normal">syn</i>-[2.2](2.6) benzothiazolophane <b style="mso-bidi-font-weight: normal">2</b> <i style="mso-bidi-font-style:normal">via</i> 10π-10π &nbsp;couplings of the quinodimethane intermediate 5, gives in practice only <i style="mso-bidi-font-style:normal">anti</i>-benzothiazolophane <b style="mso-bidi-font-weight:normal">1</b>. The structure has been established by comparison with an authentic sample of <b style="mso-bidi-font-weight:normal">1</b> recently synthesized by an unambigous route.</span>