Acylation of extended enolate ions from α-phenylthio (PhS-)crotonate esters

Rearrangements of 2-phenylthioethanols with alkenyl, alkynyl, ester, and other functionalised alkyl substituents at the migration origin: synthesis of γ-phenylthiocrotonate esters

“…The tertiary alcohol (15) dehydrated in acid to give rearranged (17) and unrearranged (19) ally1 sulphides in about equal amounts, both via the episulphonium ion (16). The symmetrical unconjugated diene (19) gave the conjugated diene We hoped that a carbonyl group at the migration origin might not prevent the formation of an episulphonium ion [e.g.…”

“…The extracts were dried (Na,SO,), evaporated, and the residue subjected to preparative t.1.c. to give the homoallyl ketone (0.81 g, 6673, RF (A) 0.45, vmax~(film) 1 700 (GO), 1 641 (C=C), and 896 cm-' (CSH,); G(CDC1,) (17), and 81 (40). The semicarbazone had m.p.…”

Synthesis of α-phenylthio enones and esters of α-phenylthio alkenoic acids

“…In the next paper" we describe related results with the esters (2). (9)-Valerophenone (23.86 g, 150 mmol) was added to a stirred suspension of anhydrous aluminium trichloride (0.15 g, 1.13 mmol) in dry ether (10 ml) under nitrogen at 0 "C. Bromine (23.55 g, 7.55 ml, 150 mmol) was added slowly, and then the mixture immediately concentrated under reduced pressure, diluted with ether (1 50 ml), and a few crystals of sodium thiosulphate added. The mixture was washed with water (50 ml) and brine (2 x 50 ml), dried (MgSO,), and evaporated under reduced pressure to give the abromo ketone30 (35.5 g, 100%) as an oil, RdCH,Cl,) 0.69.…”