Synthetic Transformations of Cycloadducts of Ethyl Thioxoacetate

The cycloadduct of anthracene and the labile thioaldehyde, ethyl thioxoacetate, has been converted into the alpha-lithio derivative with lithium diisopropylamide (LDA). Subsequent treatment with, separately, methyl iodide, ethyl iodide, allyl bromide and benzyl bromide gave the corresponding 12- 'alkyl' derivatives. Each derivative, when heated in toluene at 11