New 1,2-transpositions and alkylative 1,2-transpositions of a carbonyl group

Abstract

A new method for the 1,2-transposition and alkylative 1,Z-transposition of carbonyl groups using a-sulphenylated ketones as the starting material is described.

Synthesis of benzocyclo-octene-5,6-dione, benzocyclo-octene-5,10-dione, and 2,3-benzobishomotropone derivatives by dichlorocarbene ring enlargement, and of 7,8,9,10, tetrahydrobenzocyclo-octene-5,6-dione

“…After the usual work-up on a silica gel column with benzene as eluant, compound (20) (200 mg, 85%) was obtained, A mixture of mercuric chloride (550 mg, 2.02 mmol) and acetonitrile (8 ml) was added to a mixture of the sulphide (20) (220 mg, 1.01 mmol), acetonitrile (6 ml), and water (2 ml), and the reaction mixture was refluxed for 4.5 h under nitrogen. 27 The usual work-up gave compound (14) (35 mg, 9.2%). A mixture of compound (20) (72 mg, 0.33 mmol), hydrochloric acid ( 3 ~; 12 ml), and tetrahydrofuran (8 ml) was warmed for 5.5 h at 45 "C under nitrogen.…”